United States of America

The primary legal subdivision of the United States. The District of Columbia is treated as the statistical equivalent of a state for census purposes.

The primary legal subdivision of most states. In Louisiana, these subdivisions are known as parishes. In Alaska, which has no counties, the county equivalents are boroughs, a legal subdivision, and census areas, a statistical subdivision. In four states (Maryland, Missouri, Nevada and Virginia), there are one or more cities that are independent of any county and thus constitute primary subdivisions of their states. The District of Columbia has no primary divisions, and the entire area is considered equivalent to a county for statistical purposes.

Minor civil divisions (MCDs) - A primary governmental and/or administrative subdivision of a county, such as a township, precinct, or magisterial district. MCDs exist in 28 states and the District of Columbia. In 20 states, all or many MCD's are general-purpose governmental units: Connecticut, Illinois, Indiana, Kansas, Maine, Massachusetts, Michigan, Minnesota, Missouri, Nebraska, New Hampshire, New Jersey, New York, North Dakota, Ohio, Pennsylvania, Rhode Island, South Dakota, Vermont, and Wisconsin. Most of these MCD's are legally designated as towns or townships.

A concentration of population either legally bounded as an incorporated place, or identified by the Census Bureau as a Census Designated Place (CDP).

1. Incorporated Place - A type of governmental unit incorporated under state law as a city, town (except the New England states, New York, and Wisconsin), borough (except in Alaska and New York), or village and having legally prescribed limits, powers, and functions.
2. Census Designated Place (CDP) - A statistical entity, defined for each decennial census according to Census Bureau guidelines, comprising a densely settled concentration of population that is not within an incorporated place, but is locally identified by a name. CDPs are delineated cooperatively by state and local officials and the Census Bureau, following Census Bureau guidelines.

When appearing in parenthesis after a geographic name, such as "Houston city (part)", this term indicates that only a portion of the named geography is represented. The full name reveals the geographic context which produced the part, such as "Houston city (part), Harris County, Texas", indicating that the only the portion of Houston city within Harris County is represented.

Parts can result when two or more geographic types that do not have a hierarchical relationship (e.g., county and place) are crossed against each other to produce a new geographic type. That new geographic type contains the phrase "(or part)" to indicate the crossing of hierarchies (e.g., State-County-Place (or part)).

Metropolitan Statistical Area (MSA)

A geographic entity defined by the federal Office of Management and Budget for use by federal statistical agencies, based on the concept of a core area with a large population nucleus, plus adjacent communities having a high degree of economic and social integration with that core. Qualification of an MSA requires the presence of a city with 50,000 or more inhabitants, or the presence of an Urbanized Area (UA) and a total population of at least 100,000 (75,000 in New England). The county or counties containing the largest city and surrounding densely settled territory are central counties of the MSA. Additional outlying counties qualify to be included in the MSA by meeting certain other criteria of metropolitan character, such as a specified minimum population density or percentage of the population that is urban. MSAs in New England are defined in terms of minor civil divisions, following rules concerning commuting and population density.

Consolidated Metropolitan Statistical Area (CMSA)

A geographic entity defined by the federal Office of Management and Budget for use by federal statistical agencies. An area becomes a CMSA if it meets the requirements to qualify as a metropolitan statistical area, has a population of 1,000,000 or more, if component parts are recognized as primary metropolitan statistical areas, and local opinion favors the designation.

A geographic entity defined by the Federal OMB for use by Federal statistical agencies. If an area meets the requirements to qualify as a metropolitan statistical area (MSA) and has a population of one million or more, two or more PMSAs may be defined within it if statistical criteria are met and local opinion is in favor. A PMSA consists of a large urbanized county, or a cluster of such counties (cities and towns in New England) that have substantial commuting interchange. When two or more PMSAs have been recognized, the larger area of which they are components then is designated a consolidated metropolitan statistical area.

An area established by law for the election of representatives to the United States Congress. Each CD is to be as equal in population to all other CDs in the state as practicable, based on the decennial census counts. The number of CDs in each state may change after each decennial census, and the boundaries may be changed more than once during a decade.

In the District of Columbia and Puerto Rico, a single CD is created consisting of the entire area. The representative is termed a delegate or resident commissioner, respectively and does not have voting rights in Congress.

Data collected in these test sites were sampled at a higher rate. Most sites are equivalent to a single county; others are two or three adjacent counties.

Aggregations of standard census entities. For example, data for a user-defined neighborhood could be tabulated using census tracts as a building block. The decisions on approvals for user-defined areas will be based on confidentiality concerns.