Research Guides: Census Data and Information: About the Census

Why the Census

Why is the Decennial Census taken?

The census is used to:

determine apportionment of Congressional representatives
used to help with transportation planning
identify needs for childrens' services
distribute funds for community development.

How is it taken?

Traditionally the census is taken using two different forms. They are the:

"Short-form" is sent to every household in the United States and asks basic questions that cover relationship to head of household, type of dwelling, sex, age, and race
"Long-form" is sent to a percentage of the population and asks more in-depth questions, for example, educational attainment, ethnic origin, and income.

The 2010 Census only had a short form because the decennial long form has been replaced by the American Community Survey (ACS).

Measuring America: The Decennial Censuses From 1790 to 2000 contains copies of the census questionnaires used from 1790 to 2000.

What kind of information is collected?

The decennial census gathers demographic information of the population. Historically, other types of information have been collected about areas such as agriculture, mining, or manufacturing. Now, many of those areas are subjects of their own censuses (e.g. Agriculture, Economic, Governments) or surveys.

Geography of the Census

The basic geographical areas that have been measured over the years include the nation, states and counties. Census tracts, the smallest geographical unit measured, were created for select cities in 1910, but not included in census publications until 1940.

In 1990, census tracts were expanded to cover all counties; prior to that they covered only metropolitan and other heavily populated areas. Maps of census blocks and tracts can be found with the decennial census publications. It is important to note that only data from the short-form is available at the census block level. More detailed data can be found at the block group level. More information on census geography can be found in the Geographic Areas Reference Manual.

Cartographic boundary files
Census Geographies Here you will find most of the Census Bureau's geographic products including maps and geospatial data for legal and statistical boundaries.
Geographic Hierarchy The standard hierarchy of census geographic entities displays the relationships between legal, administrative, and statistical boundaries maintained by the U.S. Census Bureau.
Geography Reference Maps Maps that show the boundaries and names (or other identifiers) of geographic areas for which the Census Bureau tabulates statistical dat
Geographic Areas Reference Manual The Geographic Areas Reference Manual (GARM) describes in great detail the basic geographic entities the Census Bureau used in its various data tabulations for the 1990 Census and documents the purposes, definitions, standards, criteria, and procedures used to select, define, delineate, and revise those geographic entities.

About the Census

Your Guide to the Federal Census by Kathleen W. Hinckley
Call Number: HA37.U6 H556 2002 (US Government Information Reference)
ISBN: 1558705880
Publication Date: 2002-03-25

In addition to the decennial census publications, the Census Bureau publishes special subject analyses using decennial census data or reports from other surveys taken in-between decennial censuses. These publications can be identified through the Libraries' Catalog, searching for your topic using "census" as a keyword or limiting to "Bureau of the Census" as author. Many can be found on the 4th floor of McKeldin Library at U.S. Government Information SU Docs C 3.2: and some are available online on the Census Bureau's website.

The History and Growth of the United States Census, Prepared for the Senate Committee on the Census by Wright, Carroll D.
Call Number: Y 4.C 33/2:H 62
Publication Date: 1900

Census Tables Explained

Census Tables Explained

Economic Indicators

Other Sources

American Community Survey The American Community Survey (ACS) is an ongoing survey that collects detailed data from people in the 50 states, the District of Columbia, and Puerto Rico. Years: 2005 - Present

SimplyAnalytics
SimplyAnalytics contains extensive data including demographic, historic census, business, health, real estate, housing, employment, consumer spending, and marketing (over 70,000 variables total). Users can create customized maps and reports; data is down to the census tract level. Click on "Sign in as a guest" to use database. data is available at the State, County, City, ZIP Code, Census Tract and Block Group level as well as custom trade area and the entire United States. Access limited to 5 concurrent users.

Economic Census
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The economic census provides a detailed portrait of the United States' economy once every five years, from the national to the local level.

The 2007 Economic Census covers most of the U.S. economy in its basic collection of establishment statistics. There also are several related programs, including statistics on minority- and women-owned businesses. Censuses of agriculture and governments are conducted at the same time.
U.S. Census Bureau Interactive Maps
Interactive mapping tools from the U.S. Census Bureau, including Census Business Builder.
Nonemployer Statistics (NES)
Nonemployer Statistics is an annual series that provides subnational economic data for businesses that have no paid employees and are subject to federal income tax. The data consist of the number of businesses and total receipts by industry. Most nonemployers are self-employed individuals operating unincorporated businesses (known as sole proprietorships), which may or may not be the owner's principal source of income.
Statistics of U.S. Businesses
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Statistics of U.S. Businesses (SUSB) is an annual series that provides national and subnational data on the distribution of economic data by enterprise size and industry. SUSB covers most of the country's economic activity. The series excludes data on nonemployer businesses, private households, railroads, agricultural production, and most government entities.

Tabulations providing data by employment size of enterprise have been assembled as far back as 1989. The comparability of data over time may be affected by definitional changes in establishments, activity status, and industrial classifications. For more details on these changes, see the section ''Comparability With Other Data.''

These data were developed in cooperation with, and partially funded by, the Office of Advocacy of the U.S. Small Business Administration (SBA)
Census of Agriculture
The Census of Agriculture is a complete count of U.S. farms and ranches and the people who operate them. The Census of Agriculture, taken only once every five years, looks at land use and ownership, operator characteristics, production practices, income and expenditures.
Measuring America
National Historical Geographic Information System (NHGIS)
Census Bureau History
History of the U.S. Census Bureau, including history of the decennial census, includes info on innovations, good background on the different censuses
2010 SF1 documentation
2010 SF2 documentation