LibGuides: The History of Urban America: U.S. Census Data

U.S. Census Resources

American FactFinder
Data from a number of censuses and surveys from 2000 to present, retrievable by geographical location. Select "Community Facts" for quick data about an area, use "Guided Search" for some assistance drilling down to the right data, or use "Advanced Search" when you've gotten comfortable with the various surveys.
Census of Population and Housing / Decennial Census
PDF copies of the printed volumes from 1790-2010. Click through the year and available census volumes to access state-level data. Some volumes may not be available. (Note: Downloads may be quite large!)
Census 2010
A resource from the U.S. Census Bureau devoted to data from the 2010 Decennial Census. Includes data, interactive maps, and reports.
TIGERweb
Use TIGERweb to access GIS data in your browser. You can view Census Tract, Block Group, and Block boundaries from the 2010 Decennial Census.
1940 Census
Access images of the 1940 census, including data on individuals as well as maps of enumeration districts.
US Census Bureau
U.S. Geographic Summary Data and Boundary Files
'The National Historical Geographic Information System (NHGIS) provides population, housing, agricultural, and economic data, along with GIS-compatible boundary files, for geographic units in the United States from 1790 to the present." Search and download data files (you will need to create an account).

Visualization Tools

Census Explorer
Use Census Explorer to visualize data from the 1990 and 2000 Census, as well as from the 2012 County Business Patterns tables and the 2013 American Community Survey. (Requires Adobe Flash)
Social Explorer
You can use the free edition of Social Explorer to visualize data from the 2000 Decennial Census.
Interactive Maps from the U.S. Census Bureau
Web-based, interactive maps with varying levels of granularity.

US Census Resources Guide

US Census Resources Research Guide

Census Concepts and Terminology

Duquesne University comprises Census Tract 103 (data from the 2010 Decennial Census, map generated using TIGERweb).

A Census Tract is a "small, relatively permanent statistical subdivisions of a county or equivalent entity." Although census tracts may not correspond directly to geographically demarcated neighborhoods, these divisions attempt to capture smaller population sizes ("between 1,200 and 8,000 people, with an optimum size of 4,000 people"). See "Geographic Terms and Concepts - Census Tract" from the U.S. Census Bureau for more information.

Duquesne University contains Block Groups 2, 3, and 4...

...which in turn contain a number of individual blocks (data from the 2010 Decennial Census, map generated using TIGERweb).

Block Groups are composed of "clusters of blocks within the same census tract that have the same first digit of their four-digit census block number." See "Geographic Terms and Concepts - Block Groups" from the U.S. Census Bureau for more information.

See also:

Geographic Terms and Concepts - Block

Small geographic entities such as Census Tracts, Block Groups, and Blocks (or, in some cities, Block Numbering Areas) were implemented in various ways over time (see "Tracts and Block Numbering Areas" from the U.S. Census Bureau for a more detailed history). You may find that these entities remain consistent for the area you are studying over time. However, you might also discover that your area of focus contains boundaries that changed over time, or that it was subdivided into smaller geographic entities.