U.S. Census

A monthly sample household survey conducted by the Census Bureau to obtain information similar to the long-form census questionnaire. It was first tested in 1995, and replaced the long form for the 2010 Census.The nationwide survey provides annual data for social and economic characteristics for many geographic entities and population groups.

Replaced by data.census.gov in 2020. An electronic system for access and dissemination of Census Bureau data on the Internet. The system offers prepackaged data products and the ability to build user-selected tables and maps. The system serves as the vehicle for accessing and disseminating decennial/ACS data from 2000- .

The first data product from the decennial census is the apportionment population for each state and the number of representatives each state is entitled to based on the apportionment calculation.

See census block.

The features, both visible (street, road, stream, shoreline, and so forth) and invisible (county line, city limit, property line, and so forth), that delimit a census block. A boundary generally must include at least one addressable feature; that is, usually a street or road. The boundary of every legal and statistical entity recognized in the Census Bureau's standard data tabulations is a tabulation block boundary.

A statistical subdivision of a census tract. A BG consists of all tabulation blocks whose numbers begin with the same digit in a census tract; for example, for Census 2000, BG 3 within a census tract includes all blocks numbered between 3000 and 3999. The block group is the lowest-level geographic entity for which the Census Bureau tabulates sample data from the decennial census.

A large-scale map of a single census collection block, showing roads, streets, and other features, together with their names (if any) within and adjacent to the block. Field staff use block maps to guide them in their canvass of each block, to annotate map changes, and, in some areas, to mark (map spot) and number the location of each residential structure.

A number assigned to each census block. For tabulating data for Census 2000, each census block was identified uniquely within a census tract by a 4-digit number. A 1990 census block number had three digits, with a potential alphabetic suffix. The first digit identifies the block group in which the census block is located.

Prior to Census 2000, a statistical subdivision of a county or statistically equivalent entity, delineated by a state government agency or Census Bureau regional census center for the purpose of grouping and numbering census blocks in counties (and statistically equivalent entities) that did not have census tracts. BNAs were discontinued for Census 2000; they were replaced by census tracts in every county and statistically equivalent entity.

An area bounded by visible and/or invisible features shown on Census Bureau maps. A block is the smallest geographic entity for which the Census Bureau collects and tabulates 100-percent decennial census data.

A statistical entity that serves as a statistical counterpart of an incorporated place for the purpose of presenting census data for a concentration of population, housing, and commercial structures that is identifiable by name, but is not within an incorporated place. CDPs usually are delineated cooperatively with state, Puerto Rico, Island Area, local, and tribal government officials, based on Census Bureau guidelines. For Census 2000, CDPs did not have to meet a population threshold to qualify for the tabulation of census data.

A collective term referring to the geographic entities used by the Census Bureau for data collection and tabulation.

A small, relatively permanent statistical subdivision of a county or statistically equivalent entity, delineated for data presentation purposes by a local group of census data users or the geographic staff of a regional census center in accordance with Census Bureau guidelines. Designed to be relatively homogeneous units with respect to population characteristics, economic status, and living conditions at the time they are established, census tracts generally contain between 1,000 and 8,000 people, with an optimum size of 4,000 people. Census tract boundaries are delineated with the intention of being stable over many decades, so they generally follow relatively permanent visible features. However, they may follow governmental unit boundaries and other invisible features in some instances; the boundary of a state or county (or statistically equivalent entity) is always a census tract boundary.

A 4-digit basic number, followed by an optional 2-digit decimal suffix, used to identify a census tract uniquely within a county or statistically equivalent entity. For Census 2000, census tract numbers ranged from 0001 to 9999, with 9400 to 9499 reserved for census tracts related to federally recognized American Indian reservations and off-reservation trust land–primarily reservations and trust land that cross county lines.

One of 435 areas established by law for the election of people to the U.S. House of Representatives. Each district is to be as equal in population to all other districts in the state as practicable, based on the decennial census counts.

Data files generated for Congressional districts from the decennial census data and made available to the public. They contain the same types of data as the Hundred Percent Summary Files and Sample Data Summary Files.

A geographic entity designated by the federal Office of Management and Budget for use by federal statistical agencies. An area becomes a CMSA if it qualifies as a metropolitan area, has a census population of one million or more, has component parts that qualify as primary metropolitan statistical areas based on official standards, and local opinion favors the designation. CMSAs consist of whole counties except for the New England states, where they consist of county subdivisions (primarily cities and towns). See central city and statistical entity.

The primary legal division of every state except Alaska and Louisiana. A number of geographic entities are not legally designated as a county, but are recognized by the Census Bureau as equivalent to a county for data presentation purposes. These include the boroughs, city and boroughs, municipality, and census areas in Alaska; parishes in Louisiana; and cities that are independent of any county (independent cities) in Maryland, Missouri, Nevada, and Virginia. They also include the municipios in Puerto Rico, districts and islands in American Samoa, municipalities in the Northern Mariana Islands, and islands in the Virgin Islands of the United States. Because they contain no primary legal divisions, the Census Bureau treats the District of Columbia and Guam each as equivalent to a county (as well as equivalent to a state) for data presentation purposes. In American Samoa, a county is a minor civil division.

The census of population and housing, taken by the Census Bureau in each year ending in zero. Article 1, Section 2 of the Constitution requires that a census be taken every 10 years for the purpose of apportioning the U.S. House of Representatives. The first census of population was taken in 1790. The Census Bureau first conducted the census of housing in 1940.

The collective name for the censuses of construction, manufactures, minerals, minority- and women-owned businesses, retail trade, service industries, transportation, and wholesale trade, conducted by the Census Bureau every five years in years ending in 2 and 7.

A set of numeric and/or alphabetic codes issued by the National Institute of Standards and Technology to ensure uniform identification of geographic entities (and other electronic data) throughout all federal government agencies. The entities covered are states, counties, metropolitan areas, Congressional districts, named populated and other locational entities (such as places, county subdivisions, and American Indian and Alaska Native areas), and geopolitical entities of the world.

A code used to identify a specific geographic entity. For example, the geocodes needed to identify a census block for Census 2000 data are the state code, county code, census tract number, and block number. Every geographic entity recognized by the Census Bureau is assigned one or more geographic codes.

A table in the American FactFinder that provides census data for one or more selected sets of geographic entities of the same type; e.g., data for all counties in a state.

A single-family house, townhouse, mobile home or trailer, apartment, group of rooms, or single room that is occupied as a separate living quarters or, if vacant, is intended for occupancy as a separate living quarters.

Population and housing information collected for all living quarters in the United States. These questions appeared on both the short- and long-form questionnaires. The questions include age, Hispanic or Latino origin, race, relationship to the householder, sex, and whether the housing unit is owned or rented.

The decennial census questionnaire containing 100-percent and sample questions. Replaced by the American Community Survey (ACS).

The arithmetic average of a set of numbers.

The middle value in a set of numbers.

A large population nucleus, together with adjacent communities that have a high degree of economic and social integration with that nucleus. This collective term was established by the federal Office of Management and Budget (OMB) in 1990 to refer to metropolitan statistical areas, consolidated metropolitan areas, primary metropolitan statistical areas, and New England County Metropolitan Areas.

A geographic entity designated by the federal Office of Management and Budget for use by federal statistical agencies. An MSA consists of one or more counties, except in New England, where MSAs are defined in terms of county subdivisions (primarily cities and towns).

A change of a household's or person's residence from 5 years ago.

See "Public Law 94-171"

All people living in a geographic area.

A series of Census 2000 reports containing tables that report population and housing data. The series is available in printed form and on the Internet in PDF format. It is comparable to the 1990 census's CPH (Census of Population and Housing) series of reports.

The population of an area divided by the number of square miles or square kilometers of land area.

A 1975 law that requires the Census Bureau to provide state governments with selected decennial census data tabulations and related geographic products for specific geographic entities by April 1 of the year following the census. These data and products are used by the states to redefine their Congressional districts and the areas used for state and local elections–a process called redistricting.

A geographic entity for which the Census Bureau provides specially selected extracts of raw information from a small sample of long-form census records. PUMAs, which must have a minimum census population of 100,000 and cannot cross a state line, receive a 5-percent sample of the long-form records; these records are presented in state files. These PUMAs are aggregated into "super-PUMAs," which must have a minimum census population of 400,000 and receive a 1-percent sample in a national file. PUMAs for Census 2000 were delineated by state officials, and comparable officials in the District of Columbia and Puerto Rico. The Census Bureau provided a single 10-percent sample file each for Guam and the Virgin Islands of the United States.

Computerized files containing a small sample of individual long-form census records showing the population and housing characteristics for the unidentified people included on those forms. The records are screened to maintain confidentiality.

The redistribution of seats in the U.S. House of Representatives among the several states on the basis of the most recent decennial census, as required by Article 1, Section 2 of the Constitution.

The process of revising the geographic boundaries of areas from which people elect representatives to the U.S. Congress, a state legislature, a county or city council, a school board, and the like to meet the legal requirement that such areas be as equal in population as possible following a census.

Census data derived from additional questions asked of about 17 percent of the population on the long-form questionnaire for Census 2000, and on a continuous basis for areas covered by the American Community Survey. The person questions cover social characteristics, such as ancestry, disability, grandparents as caregivers, education, marital status, and veteran status, and economic characteristics, such as 1999 income and work status and industry, occupation, and class of worker. The housing questions cover physical characteristics, such as the number of rooms, type of heating fuel, and telephone service availability, and financial characteristics, such as rent, mortgage, utilities, taxes, and fuel costs.

An error that occurs because only part of the population is contacted directly. As with any sample, differences are likely to exist between the characteristics of the sampled population and the larger group from which the sample was chosen. Sampling error, unlike nonsampling error, is measurable.

The decennial census questionnaire containing only the 100-percent questions.

A federal census conducted at the request and expense of a local governmental agency to obtain a population count between decennial censuses.

A type of minor civil division in 16 states. In some states, many or all townships are nonfunctioning entities. In Michigan, some townships are legally designated as "charter townships."

See census tract.

See census tract number.