2-Year College Degree
Percentage of population (over the age of 25) with an Associates Degree or another recognized 2 year degree.

Air Quality

Altitude

Anticipated Future Job Growth
The projected change in job availability over the next 10 years.

Average Household Size
The average number of persons residing within a household in a particular area. It is computed by dividing the total population in households (excluding group quarters such as correctional facilities, nursing homes and college dormitories) by the total number of occupied housing units in that area.

Average Income Per Capita
The demographic, "average income per capita", refers to the average income per person.

Consumer Price Index (CPI)
A concept developed by the US Bureau of Labor Statistics. It is used to measure average changes in prices over time of a fixed market basket of goods and services. Regional CPIs such as that for the Washington, DC area cannot be used to compare cost of living differences among regions.

Cost of Living Index
The overall cost of living for an area where the national average is equal to 100.

Employed
Those persons 16 years old and older who are currently holding income producing jobs.

Expenditures per Student
The dollar amount the local school district allocates in expenditures for each student.

Graduate Degree
Percentage of population (over the age of 25) with a Master Degree, Phd., or other recognized advanced degree.

Health Cost Index
Uses the standard daily rate of a hospital room + the cost of one doctors visit + one dental checkup.

High School Graduates
Percentage of population (over the age of 25) with a high-school diploma or high-school equivalency degree.

Home Appreciation Percent
The average percentage change in the value of an area's homes within a period of one year.

Household
A household includes all persons who occupy a housing unit. A household is an occupied housing unit and includes all persons who occupy that single housing unit. A household may be comprised of one or more families, one or more unrelated individuals, or a combination of families and unrelated individuals.

Household Income
The demographic, "household income", is the combined gross money income of all persons who occupy a single housing unit. The household income can be comprised of the gross money income earned by one or more families, one or more unrelated individuals, or a combination of families and unrelated individuals who occupy a single housing unit.

Housing Unit
A housing unit is defined as a house, apartment, mobil home, group of rooms, or a single room that is occupied (or, if vacant, is intended for occupancy) as a separate living quarters. (A recreational vehicle, van, trailer, boat, tent, or the like, if occupied as someon's usual place of residence, also counts as a housing unit.)

Separate living quarters are those in which the occupants live and eat separately from any other persons in the building, and which have direct access from the outside of the building or through a common hall. The occupants may be a single family, one person living alone, two or more families living together, or any other group of related or unrelated persons who share living arrangements, unless there are nine or more persons unrelated to the person in charge, in which case the living space is classified as group quarters. Occupants of group quarters (dormitories, barracks, institutions, etc., excluding any staff quarters that satisfy the housing-unit criteria) are by definition not household members.

Income Tax
The total of all income taxes for an area, including: State, County, and Local. This does not include Federal Taxes.

Market basket - Consumer Price Index
The market basket is a package of goods and services that consumers purchase for day-to-day living. The weight of each item is based on the amount of expenditure reported by a sample of households.

Mean Age
Mean Age is the mathematical average age of all the members of a population.

Median
Median is the middle value in an ordered range of numbers. The median divides a distribution into two equal parts, one half having values above and one half having values below the middle value.

The median is a better indicator than the average, because a few values on either end do not effect the median value.
If the number of values is even, it is half the sum of the two middle numbers.

Median Age
Median Age is the age that divides a population into two numerically equal groups; that is, half the people are younger than this age and half are older.

Median Age of Homes
The median age of homes in a geographic area.

Median Home Value
The median value of home sales for a period of one year.

Median Household Income
Median income of households in the defined area.

Not Employed
Not employed (American Time Use Survey) The term refers to persons who are classified as unemployed as well as those classified as not in the labor force.

Not In Labor Force
The demographic, "not in labor force", includes persons aged 16 years and older in the civilian noninstitutional population who are neither employed nor unemployed. Information is collected on their desire for and availability for work, job search activity in the prior year, and reasons for not currently searching.

People Per Household
People Per Household refers to the average number of persons residing within a household in a particular area. It is computed by dividing the total population in households (excluding group quarters such as correctional facilities, nursing homes and college dormitories) by the total number of occupied housing units in that area.

Per Capita
Per Capita refers to a unit of population; per person.
Average Income Per Capita = Average income per person

Percent Commuting by Bus or Train
The percentage of the population commuting to work by mass transit. This includes: Bus, Trains and Ferry.

Percent Commuting by Car
The percentage of the population commuting to work as sole occupant in car.

Percent Commuting by Carpool
The percentage of working population commuting by carpool.

Percent Female
Percent Female is the percentage of females in a defined area.

Percent Male
Percent Male is the percentage of males in a defined area.

Percent Married
Percentage of population that is over 15 years old and married.

Percent of Vacant Homes
The percentage of housing units that are unoccupied.

Percent Owning Home
The percentage of housing units that are owned by the occupant.

Percent Renting Home
The percentage of housing units that are rented by the occupant.

Percent Single
Includes divorced people and never married people.

Percent Working at Home
Percentage of population that uses their home as their primary place of work.

Personal Income
The demographic, "personal income", is a concept developed by the US Bureau of Economic Analysis. It is a broader income concept than adjusted gross income or money income. Personal income consists of wage and salary disbursements, profits from businesses that are not corporations, net rental income, dividends, personal interest income, and transfer payments (such as pensions and welfare assistance). It includes wages and salaries paid in-kind, the net rental value of owner-occupied houses, and the net value of food and fuel produced on farms. Capital gains are not included because they are not attributable to current economic activity.

Physicians per capita
Number of physicians per 100,000 people.

Population
Population, a term used in demographic data, refers to a group of people per area.

Population Density
Population density refers to the population per unit of land area.
Example: People per square mile or people per square kilometer of arable land.

Property Crime
Property crimes do not involve force or threat to an individual's person.
For example: Motor Vehicle Theft or Arson

Property Crime Risk
The index of risk of Property Crime where 10 represents the highest and 0 the lowest.

Recent Job Growth
The percentage increase or decrease of available jobs in a one year period.

Students per Guidance Counselor
The number of overall students assigned to overall Guidance Counselors.

Students per Librarian
The number of overall students assigned to Librarians and Media Specialists.

Students per Teacher
The number of overall students assigned to overall teachers.

Superfund Site Index

Unemployed Persons
Unemployed Persons are civilians in the labor force 16 years old and older who do not currently hold jobs but are actively looking for work and are available to accept employment.

Unemployment Rate
The number of available workforce that is not employed.

UV Index

Violent Crime Risk
The index of risk of Violent crime where 10 represents the highest and 0 the lowest. Violent crimes involve force or threat of force.
For example: Murder or Rape.

Watershed Quality

Zip Code
Zip Code is defined as administrative units established by the United States Postal Service (USPS) for the efficient distribution of mail. ZIP codes generally do not respect political or census statistical area boundaries, nor do they usually have clearly identifiable boundaries. In addition, ZIP codes often serve a continually changing area and are changed periodically to meet postal requirements and do not cover all the land area of the United States. The first three digits of the five-digit code identify a major city or sectional distribution center while the last two digits signify a post office deliver area or point.

Environment & Topography
The following terms are defined below:

Air Quality
Watershed Quality
Superfund Site Index
UV Index
Altitude

What is Air Quality and Air Pollution?
Air pollution comes from many different sources such as factories, power plants, dry cleaners, cars, buses, trucks and even windblown dust and wildfires. Air pollution can threaten the health of human beings, trees, lakes, crops, and animals, as well as damage the ozone layer and buildings. Air pollution also can cause haze, reducing visibility in national parks and wilderness areas. The Environmental Protection Agency (EPA) protects human health and the environment through the regulatory process and voluntary programs such as Energy Star and Commuter Choice. Under the Clean Air Act, EPA sets limits on how much of a pollutant is allowed in the air anywhere in the United States. Although national air quality has improved over the last 20 years, many challenges remain in protecting public health and the environment. EPA's goal is to have clean air to breathe for this generation and those to follow.

Air Quality Index (AQI) - A Guide to Air Quality and Your Health
The AQI is an index for reporting daily air quality. It tells you how clean or polluted your air is, and what associated health effects might be a concern for you. The AQI focuses on health effects you may experience within a few hours or days after breathing polluted air. EPA calculates the AQI for five major air pollutants regulated by the Clean Air Act: ground-level ozone, particle pollution (also known as particulate matter), carbon monoxide, sulfur dioxide, and nitrogen dioxide. For each of these pollutants, EPA has established national air quality standards to protect public health. Ground-level ozone and airborne particles are the two pollutants that pose the greatest threat to human health in this country.

How Does the AQI Work?
Think of the AQI as a yardstick that runs from 0 to 500. The higher the AQI value, the greater the level of air pollution and the greater the health concern. For example, an AQI value of 50 represents good air quality with little potential to affect public health, while an AQI value over 300 represents hazardous air quality.

An AQI value of 100 generally corresponds to the national air quality standard for the pollutant, which is the level EPA has set to protect public health. AQI values below 100 are generally thought of as satisfactory. When AQI values are above 100, air quality is considered to be unhealthy - at first for certain sensitive groups of people, then for everyone as AQI values get higher.

Understanding the AQI
The purpose of the AQI is to help you understand what local air quality means to your health. To make it easier to understand, the AQI is divided into six categories:


0	to	50	= Good
51	to	100	= Moderate
101	to	150	= Unhealthy for Sensitive Groups
151	to	200	= Unhealthy
201	to	300	= Very Unhealthy
301	and above		= Hazardous

Each category corresponds to a different level of health concern. The six levels of health concern and what they mean are:

0 to 50 = Good
The AQI value for your community is between 0 and 50. Air quality is considered satisfactory, and air pollution poses little or no risk.

51 to 100 = Moderate
The AQI for your community is between 51 and 100. Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people. For example, people who are unusually sensitive to ozone may experience respiratory symptoms.

101 to 150 = Unhealthy for Sensitive Groups
When AQI values are between 101 and 150, members of sensitive groups may experience health effects. This means they are likely to be affected at lower levels than the general public. For example, people with lung disease are at greater risk from exposure to ozone, while people with either lung disease or heart disease are at greater risk from exposure to particle pollution. The general public is not likely to be affected when the AQI is in this range.

151 to 200 = Unhealthy
Everyone may begin to experience health effects when AQI values are between 151 and 200. Members of sensitive groups may experience more serious health effects.

201 to 300 = Very Unhealthy
AQI values between 201 and 300 trigger a health alert, meaning everyone may experience more serious health effects.

301 and above = Hazardous
AQI values over 300 trigger health warnings of emergency conditions. The entire population is more likely to be affected.

To find your Air Quality Report:
Air Quality Reports provide forecast air quality ratings for today and tomorrow. This information is from the U.S. Environmental Protection Agency. Only cities that report to the EPA are represented on the forecast pages. Note that some cities report only seasonally. Cities will disappear from the Air Quality Forecast list anytime they are not reporting to the EPA. Air Quality Reports are available between May and September for most cities.

Select a town on the Westchester Towns home page.
Your weather report box is displayed.
Click on your Town Name and State.
Example: Pound Ridge, NY
A new screen will appear.
Click on Healthy Living: Air Quality & Pollution
Follow directions to find you Air Quality Report.

What is Watershed Quality and Watershed Management?
According to the Conservation Technology Information Center, a watershed is "the area of land that catches rain and snow and drains or seeps into a marsh, stream, river, lake or groundwater. Watersheds come in all shapes and sizes. Just as creeks drain into rivers, watersheds are nearly always part of a larger watershed."

Center for Watershed Protection
The CWP provides "local governments, activists, and watershed organizations around the country with the technical tools for protecting some of the nation's most precious natural resources: our streams, lakes, and rivers." Its multidisciplinary strategy for watershed protection "encompasses watershed planning, watershed restoration, stormwater management, watershed research, better site design, education and outreach, and watershed training."

Water Quality: Wetland Acres
The existence of a well balanced non-tidal wetland complex is a sign of a healthy water flow ecosystem. Non-tidal wetlands help water systems to absorb stormwater during flood events, remove nutrients, sediments, and other pollutants from the water, and provide unique habitat for plants and animals which depend upon these areas, including many rare species of reptiles and amphibians.

Non-tidal wetlands are lost due to land development, highway building, and other projects that directly impact waterways. Indirect impacts also occur when upland and nearby development redirect drainage patterns, increases surface runoff, and reduces groundwater inflows to negatively impact the hydrologic regime critical to a viable wetland environment. When surface runoff and groundwater flows to wetlands are substantially altered, many vital wetland functions can be lost.

Stream Conditions
Healthy and diverse aquatic biological communities, along with high quality in-stream and riparian habitat, are indicators of the condition of our streams and watersheds. The biological community living in a stream reflects the cumulative impacts of human activities and landscape processes in the watershed.

A decline in the condition of our streams results in a reduction in biodiversity within our landscape, as more diverse fish and insect communities are reduced to a community with mostly pollutant and stress tolerant species. A decline in stream condition also generally reflects an increase in human induced impacts in a watershed that are not being adequately managed, such as increases in stormwater runoff, stream erosion and sedimentation, warming of stream temperatures from paved areas and inadequate forested buffers, pollutant loads and trash dumping. These watershed impacts reduce the aesthetic and recreational value of our natural resources, and contribute to the degradation of downstream resources. Reduced stream quality, manifested in increased sediment, nutrient, or other pollutant loadings, also impacts water supply reservoirs and treatment costs of water withdrawn from other watersheds to support public water supply needs.

Watershed Rules and Regulations to Protect New York City’s Drinking Water Supply
The Memorandum of Agreement contains updated Watershed Rules and Regulations which are designed to ensure the continued, long-term protection of New York City’s drinking water supply and minimize, to the extent feasible, adverse impacts on the Watershed communities. The Watershed Regulations are designed to reduce current contaminants and prevent the introduction of new sources of contamination to the drinking water supply. The Watershed Regulations work in conjunction with existing federal and state regulations and provide additional regulations tailored to the watershed area itself.

What is Superfund?
Superfund is the federal government's program to clean up the nation's uncontrolled hazardous waste sites. Superfund is the name given to the environmental program established to address abandoned hazardous waste sites. It is also the name of the fund established by the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) of 1980. This law was enacted in the wake of the discovery of toxic waste dumps such as Love Canal and Times Beach in the 1970s. It allows the EPA to clean up such sites and to compel responsible parties to perform cleanups or reimburse the government for EPA-lead cleanups.

Who Implements Superfund?
EPA's Office of Solid Waste and Emergency Response (OSWER) in Washington, D.C. oversee the Superfund program. The Office of Emergency Management within OSWER is responsible for short term responses conducted under the authority of Superfund. The Office of Superfund Remediation and Technology Innovation, and the Federal Facilities Response and Reuse Office, also within OSWER, have the lead for managing the long-term Superfund response program, the latter for responses involving Federal Facilities. In addition, OSWER manages the federal Brownfields program.

The 1978 discovery of toxic chemicals beneath the suburban infrastructure of Love Canal, in Niagara Falls, New York first illuminated the consequences of environmental neglect. For decades, many American businesses had disposed of hazardous waste improperly, contaminating tens of thousands of sites nationally, including nearly 250 within Region 2 alone. Accidents, spills, and leaks of hazardous materials resulted in land, water, and air that pose immediate and potential threats to public and environmental health.

EPA Region 2
Serves: New Jersey, New York, Puerto Rico, US Virgin Islands and 7 tribes.

Citizen reaction to these localized threats led Congress to establish the Superfund Program in 1980, an initiative designed to locate, investigate, and clean up the most hazardous sites nationwide. Superfund is officially called CERCLA, or the Comprehensive Environmental Response, Compensation, and Liability Act. The EPA administers the Superfund Program in cooperation with individual states and tribal governments. Superfund constitutes a crucial environmental and economic precedent within American legislative history.

What is the UV Index?
Some exposure to sunlight can be enjoyable; however, too much could be dangerous. Overexposure to the sun’s ultraviolet (UV) radiation can cause immediate effects, such as sunburn, and long-term problems, such as skin cancer and cataracts. The UV Index, which was developed by the National Weather Service and the U.S. Environmental Protection Agency (EPA), provides important information to help you plan your outdoor activities to prevent overexposure to the sun’s rays. The UV Index provides a daily forecast of the expected risk of overexposure to the sun. The Index predicts UV intensity levels on a scale of 1 to 11+, where 1 indicates a low risk of overexposure and 11+ signifies an extreme risk. Calculated on a next-day basis for every ZIP Code across the United States, the UV Index takes into account clouds and other local conditions that affect the amount of UV radiation reaching the ground in different parts of the country. To locate the UV Index for your town - visit your town's home page and review the weather statistics as follows:

Click on the Explore a Town banner at the top of this page.
Select your community from Westchester Communities.

UV Index Number Exposure Level
2 or less = Low
3 to 5 = Moderate
6 to 8 = High
8 to 10 = Very High
11+ = Extreme

By taking a few simple precautions daily, you can greatly reduce your risk of sun-related illnesses.

Do Not Burn
Avoid Sun Tanning and Tanning Beds
Generously Apply Sunscreen with an SPF of at least 15
Wear Protective Clothing, Including a Hat, Sunglasses, and Full-Length Clothing
Seek Shade
Use Extra Caution Near Water, Snow and Sand
Watch for the UV Index
Get Vitamin D Safely
Early detection of melanoma can save your life. Carefully examine ALL of your skin once a month. A new or changing mole in an adult should be evaluated by a dermatologist.

What is Altitude?
Altitude is the height expressed as the distance above a reference point, which is normally sea level or ground level.

Source: Environmental Protection Agency
Click for more information on any of the above environmental topics. You will find information about Superfund sites in your area, the health effects of common contaminants, cleanup efforts, and how you can become involved in cleanup activities in your community.

Sales Tax

Sales Tax for Westchester County (With the exception of following 4 locations) = 7.375%
Mount Vernon (city) = 8.375%
New Rochelle (city) = 8.375%
White Plains (city) = 7.875%
Yonkers (city) = 8.375%


Westchester and Town/City rates are current as of 1/13/2009.
National Sales Tax rate is as of: 2007


Notes:
Rate includes the Tax imposed for the benefit of the Metropolitan Commuter Transportation District.

Add an additional 5% to the combined state and local sales tax rate for certain short term passenger car rentals or sales of entertainment or information services provided by telephone or telegraph which are received exclusively in an auditory manner over the telephone or telegraph.

Note: The Consumer Price Indexes (CPI) program produces monthly data on changes in the prices paid by urban consumers for a representative basket of goods and services.

A cost-of-living index is a conceptual measurement goal, however, not a straightforward alternative to the CPI. A cost-of-living index would measure changes over time in the amount that consumers need to spend to reach a certain "utility level" or "standard of living."

Both the CPI and a cost-of-living index would reflect changes in the prices of goods and services, such as food and clothing, that are directly purchased in the marketplace; but a complete cost-of-living index would go beyond this to also take into account changes in other governmental or environmental factors that affect consumers' well-being. It is very difficult to determine the proper treatment of public goods, such as safety and education, and other broad concerns, such as health, water quality, and crime that would comprise a complete cost-of-living framework.

Traditionally, the CPI was considered an upper bound to a cost-of-living index in that the CPI did not reflect the changes in buying or consumption patterns that consumers would make to adjust to relative price changes. The ability to substitute means that the increase in the cost to consumers of maintaining their level of well-being tends to be somewhat less than the increase in the cost of the mix of goods and services they previously purchased.

Since January 1999, a geometric mean formula has been used to calculate most basic indexes within the CPI; in other words, the prices within most item categories (e.g., apples) are averaged using a geometric mean formula. This improvement moves the CPI somewhat closer to a cost-of-living measure, as the geometric mean formula allows for a modest amount of consumer substitution as relative prices within item categories change.

Since the geometric mean formula is used only to average prices within item categories, it does not account for consumer substitution taking place between item categories. For example, if the price of pork increases compared to those of other meats, shoppers might shift their purchases away from pork to beef, poultry, or fish. The CPI formula does not reflect this type of consumer response to changing relative prices. In 2002, as a complement to the CPI-U and CPI-W, BLS began producing a new index intended to more closely approximate a cost-of-living index by reflecting substitution among item categories. It is unlikely, however, that the difficult problems of defining living standards and measuring changes in the cost of their attainment over time will ever be resolved completely.

Source: U.S. Department of Labor, Bureau of Labor Statistics

Health Cost Index & Health Cost Index Report
The Health Cost Index® (HCI) is Milliman's proprietary measure of healthcare cost increases. First published in 1988, the HCI is based on data gathered from the providers of healthcare (e.g., hospital, physicians, pharmacies) to capture changes in healthcare costs per capita for the overall population (excluding Medicare). The HCI is available by type of benefit (hospital, physician, prescription drug).

The Health Cost Index Report® (HCIR) employs data through the previously ended quarter, making it a timely source of information on healthcare trends. It incorporates changes in utilization and intensity that are not reflected in the standard medical price indices. More importantly, the HCIR provides projections of the direction and relative change in future healthcare trends, based on economic variables that explain the movement of healthcare costs.

The HCIR represents the latest trends and forecasts from our proprietary database of medical trends. These trends measure the market average rate of increase in medical costs for a typical $250-deductible comprehensive major medical benefit package. Our database measures the growth rate in medical consumption by measuring how fast provider net revenues increase. This inherently captures price, utilization, and mix/intensity of service changes (technology). The HCIR presents trends by benefit and by region of the country. Various levels of detail are available for benchmarking or forecasting healthcare trends of various payers.

Source: Milliman, Inc. Statistics

Source of Definitions:

Environmental Protection Agency
Click for more information on any of the above environmental topics. You will find information about Superfund sites in your area, the health effects of common contaminants, cleanup efforts, and how you can become involved in cleanup activities in your community.


New York State Department of Taxation and Finance
U.S. Bureau of Labor Statistics, Division of Information Services
Thomson Scientific & Thomson Corporation

Demographics Index Pages

It is believed that the Town of North Castle was originally inhabited by the Siwanoy, part of the Wappinger Confederacy and members of the Algonquin nation. The Siwanoy were taken by force in 1644 by Europeans. In the early 1700s, King William gave his favorite courtiers the West Patent, of which the western portion of North Castle was a part, and the Middle Patent, the eastern part of North Castle. At one time, North Castle included all the territory that became incorporated as New Castle in 1791. The territory comprising both towns was once part of the Parish of Rye organized in 1693.

The area quickly became a refuge for people fleeing from religious persecution. People from Massachusetts and Connecticut settled the eastern part of North Castle, while Quakers from Rye and Long Island gathered in Armonk. By 1730, North Castle was an established settlement.

The Town of North Castle was incorporated on March 7, 1788. North Castle's name is said to derive from a barrier built by the Mohican people to protect themselves from enemy attacks which stood on the hillside now occupied by the international headquarters of I.B.M. Corporation. They called the site "North Fort" and European settlers later gave it the name of North Castle. The name Armonk is derived from another Mohican word, 'Cohamoog', which means 'the wide, flat place where the water runs'.

During the American Revolution, New and North Castle were officially considered neutral territory. However, the area was strongly patriotic. One significant Revolutionary War conflict did occur in North Castle, "The Battle of White Plains". This battle of October 28, 1776 was a series of short skirmishes between General George Washington's small American army and General William Howe's much larger British & Hessian force. Although the British eventually won the confrontation, forcing Washington's troops to retreat, Howe never followed up this advantage by pursuing and capturing the American army. Thus, the battle served as a delaying action that allowed Washington's troops to withdraw to safety in New Jersey. As a result, many historians feel that the battle marked an important turning point in the war.

During the Revolutionary War, the Elijah Miller house in North White Plains served, several times, as the headquarters of General George Washington. A few miles to the west (now known as Mount Kisco) St. George's Church (North Castle Church) served as a camp and hospital. A young Frenchman's diary dated July 6, 1781, reported of the area: "This whole country gives evidence of the horrors of war... All the Whigs here have abandoned their houses. Among them are some very handsome ones, deserted, half destroyed, or burned, with untended orchards and gardens filled with fruits and vegetables and driveways overgrown with grass two feet high."

Point of Interest: Press here for "People of the The American Revolution"

Point of Interest: Smith's Tavern in Armonk is believed to have been built in the late 1700's. John Smith, a former captain in the Continental Army, operated the house as a tavern, site of town meetings, colonial militia headquarters, post office, and stopping place for the Danbury stage as early as 1797. Smith's son Samuel continued to operate the tavern until his own death in 1884. Since 1974, the building has belonged to the North Castle Historical Society and is now open to the public as a museum.

During the early part of the 19th century, most North Castle residents were farmers. However, several small "cottage industries" did exist. For example, some farmers supplemented their income by becoming shoemakers or shirtmakers. The coming of the railroad in the 1840's marked the beginning of the shift away from the region's agricultural way of life. However, towns without the railroad, such as North Castle, suffered economically. North Castle was also hurt economically by the Industrial Revolution since new manufacturing techniques made the local cottage industries impractical. From 1860 to 1900, North Castle's population declined from 2,200 to 1,470.

Point of Interest: The Underground Railroad, which helped runaway slaves travel to freedom in Canada, operated a "station" between Armonk and North White Plains.

By the early 20th century, North Castle's economy improved dramatically due to the New York City purchase of reservoir land and the building of the Kensico Dam in Valhalla (1909-1915) which used North Castle granite. Many of the European immigrant stone masons who built the dam later settled in the town's Quarry Heights section.