1990 Census of Population and Housing:

User Guide and Tutorial: Step 2

The second step in determining what report contains the data you need is to determine if you want the data organized by state, city, metropolitan area or by some other geographic breakdown.  Using Census data correctly requires a clear understanding of Census geographic terminology simply because all Census data are organized by geographic entities.

Not all geographic entities are provided in all of the Census reports.   Some reports only provide data by state while other Census reports break data down to the block level.  Use the following information to determine how you want the data broken down.

The Census Bureau organizes geographic entities into hierarchies.   The following illustrates basic Census geography from the 1990 Census:

Block
An area bounded on all sides by visible features, such as streets, roads, streams, and occasionally by invisible boundaries, such
as a township line. The entire country has been blocked in 1990.

Block Group (BG)
A group of blocks for tabulation purposes. Replaces the Enumeration District concept for rural areas in previous censuses.

Block Numbering Area (BNA)
An area delineated cooperatively by the States and Census Bureau for grouping blocks where census tracts have not been established (e.g. outside metropolitan areas). The entire country will have census tracts or BNA's in 1990.

Census County Division (CCD)
Replaces MCD's in states where they are not adequately defined.

Census Designated Place
An unincorporated concentration of population with a definite residential nucleus, such as University City.

Census Tract
A statistical subdivision of a metropolitan area with an average of 4,000 inhabitants. Defined by local committees to approximate a neighborhood.

Congressional Districts
Congressional voting districts for the 101st Congress, 1989-90; 103rd Congress, 1993-94, and 104th Congress, 1995-96.

Consolidated Metropolitan Statistical Area (CMSA)
Two or more contiguous MSA's (see MSA definition below).

County Equivalent
A geographic entity not legally referred to as a county but treated as such for data tabulation purposes.

Indian Reservations
Federally-defined Indian reservations, which may cross state boundaries, as well as Alaskan Native villages.

Metropolitan Statistical Area (MSA)
A city of over 50,000 inhabitants together with the county in which it is located and contiguous counties which are economically and socially integrated with the central city. It may also consist of an urbanized area of 50,000 with a total metropolitan area population of at least 100,000.

Minor Civil Division (MCD)
The primary political and administrative subdivision of a county in 28 states. They may be designated as township, town, borough, magisterial district, or gore. The link is to the first of five tables arranged by size category.

Nation
The United States includes 50 states, the District of Columbia, and outlying areas.

Place
A city, town, township, or village.

Primary Metropolitan Statistical Area (PMSA)
An MSA component of a Consolidated Metropolitan Statistical Area.

Public Use Microdata Areas
County groups or portions of MSAs with 100,000 or more inhabitants.

Rural Area
All geographic areas not covered immediately above.

School Districts
School Districts as defined by states and local communities.

Urban Area
Urbanized Areas plus all places of over 2,500 inhabitants.

Urbanized Area
A central city plus the closely-settled urban fringe that together have a minimum population of 50,000.

Zip Codes
Postal zip codes identified for mail delivery, rather than physical location, as of April 1990. Many zip codes changed as a result of the Census but those changes are not reflected in the data products.