Census data is grouped thematically into tables of varying detail. Each table has a unique ID which also indicates how broad or narrow it is. Prefixes for the most common tables in the decennial census and American Community Survey are shown below. Data profiles are broadest and fewest in number, and are a good place to start. Detailed tables are the most narrow and focused. Data profile and summary tables include both counts and percent totals, while the detailed tables only include counts.
Every table measures a specific universe or subset of the population. In the employment status table below, the universe is the population 16 years and older, and the first Total row represents this group. The universe is based on what's logical for the variables being summarized; the 16+ population represents the eligible working age population in the US, so employment is measured relative to this population. Subcategories are represented by indentation and facets in variable labels. For example, the labor force and population not in the labor force are subsets of the total universe, while the civilian labor force and the armed services are subsets of the labor force.
These are the primary census summary datasets for population and housing. These links take you to the program page for the data; to access and download decennial census or ACS data use the portals listed further below. For more details about the datasets, see Exploring U.S. Census Datasets: A Summary of Surveys and Sources.
US census data is free and in the public domain. Use data.census.gov to access the full range of tables from the decennial census, ACS, and many other datasets. See the tutorials below to learn how to effectively use it. Visit the alternatives if you just need some basic stats.
The library subscribes to a number of proprietary databases that make accessing and visualizing census data a bit easier, and they provide extra functions for thematic mapping and analysis. Members of the Brown University community have access to the following: