Census of Population and Housing

American Community Survey



Early on one of the criticisms leveled against the Decennial Census was its timeliness.  In 1996 the Census Bureau began developing a new statistical product - the American community Survey (ACS) to address this issue.  After a decade of testing and development, ACS went live in January 2005

While some question its legality and object to the intrusive nature of some of its questions, the main purpose of the ACS is to provide insight into the changing social and economic characteristics of the nation. The Census Bureau considers it part of the Decennial Census.  In 2010 the ACS replaced the Decennial Long Form used for seventy years to provide detailed social and economic information. Like the Decennial Census, it is confidential and mandatory.

Unlike the Decennial, it is an estimate.  The ACS is designed to provide up-to-date demographic, housing, social and economic data.  But because it is an estimate it can be prone to sample error and distortions. 

The ACS is sent out to a small percentage of the population on a rotating annual basis thus providing an ongoing assessment of the nation, its inhabitants, etc.  It is national and continuous and asked of more than 3.5 million randomly selected addresses. Roughly one in forty households.

The survey consists of between 96 and 263 questions depending on the number of persons living in a household. The questions asked vary slightly survey to survey depending on the data needs of various federal agencies. Originally administered in a paper format, starting in 2020 an online version became available. 

ACS data is updated yearly.  Working with a very sophisticated algorithm, the Census Bureau using a very small sample provides real time demographic information.  Because estimates are inherently subject to sampling error and uncertainty, the Census Bureau routinely includes margin of error information in its ACS data tables. Originally, data was available as 1-year, 3-year and-5 year estimates. After 2013, ACS 3-year estimates have been discontinued.  The 5-year estimates are a rolling total, and as new data becomes available, old data is dropped from the estimate. In 2020 in response to the COVID-19 Pandemic, the Census Bureau instead of releasing its full suite of 1-year estimates, released a limited number of data tables extrapolated from the 2020 ACS. These table unlike earlier ACS results are not available from data.cenus.gov, but rather on a separate page.


When selecting between 1-year, and 5-year estimates consider the following points:

  • Area’s population
  • Level of Reliability
  • How Current of an estimate is needed

Not sure where to start?  Try:

American Community Survey (ACS):   Subject included in the Survey.  (United States Census Bureau)  A list of topics covered in the ACS with links to tables in American FactFinder with data pertaining to the topic.

The resources listed below can help in locating American Community Survey data.  Please check the OSU Libraries’ catalog for location and availability where necessary.


Research Guides

American Community Survey (ACS). (United States. Census Bureau)


Census Research Guide:  American Community Survey.  (University of California – San Diego. The Library)


LibGuide - American Community Survey (ACS):  About the ACS. (Southern Illinois University – Edwardsville. Lovejoy Library)


Interactive Databases

ACS Summary File. (United States. Census Bureau) is available in comma-delimited format text files from 2005 to the present.


ACS Public Use Microdata Sample (PUMS).  (United States. Census Bureau) Data is available for the ACS in 1-, 3- and 5-year estimates from 2005 on.


Data-Plant Statistical Datasets. [Also called ProQuest Statistical Datasets, Lexis-Nexis Statistical Datasets, or Statistical Datasets.  Restricted to OSU Affiliates]  Provides access to statistical information from federal agencies, etc.  Coverage varies with statistical source.  Census data from 1970’s on.


Data.census.gov. (United States. Census Bureau)  Replaced American Fact Finder and Dataferrett as the search engine for current American Community Survey (ACS) data.  Can customize searches and how results are displayed.


Geolytics. (GeoLytics, Inc.)  Available by appointment.  Provides demographic data, census demographics including ACS, market research data, and geocoding.


Missouri Census Data Center.  (Missouri State Library)  Census data from 1980-ACS including current ACS data for the United States and by state.  Some parts are still under construction.


NHGIS - National Historical Geographic Information System.  (University of Minnesota, Minnesota Population Center)  Provides, free of charge, aggregate census data and GIS-compatible boundary files for the United States between 1790 and 2012.


Social Explorer. (Social Explorer) [Available on OSU Libraries Research Databases. Must be OSU Affiliate]  Provides quick and easy access to current and historical census data and demographic information. The easy-to-use web interface lets users create maps and reports to illustrate, analyze, and understand demography and social change.


Other Resources

Data Tools and Apps. (United States Department of Commerce. Bureau of the Census)
Links to census related databases, etc.  Titles released after June 23, 2014 are available from Publications.


Statistical Abstract of the United States.  Washington, D.C.:  G.P.O., 1878-2012 incomplete.  [Note as of October 2011, the Bureau of Census stopped publishing this title.  ProQuest  took over publication.  
Online 1870-2011  |  2012  |   2013-
Annual.   Data drawn from a variety of sources including the Censuses of Population and Housing. Most tables are national, some state and metropolitan area tables. Available both in hard copy and CD-ROM, although the electronic version is incomplete. 


Further Reading

American Community Survey:  Design and Methodology.   United States Census Bureau.  Washington, D.C.:  U.S. Department of Commerce, Bureau of the Census, January 30, 2014.


American Community Survey (ACS):  What is the American Community Survey? (United States Department of Commerce. Bureau of the Census)


Compass for Understanding and Using American Community Survey Data:  What General Data Users Need to Know.  United States. Census Bureau.  Washington, D.C.:  U.S. Government Printing Office, October 2008.  (There are other titles in this series with slightly different slants intended for different audiences.  


Handbooks for Data Users has the complete list of titles available with information on the intended audiences.


Understanding and Using American Community Survey Data:  What all Data Users Need to Know.  U.S. Census Bureau.  Washington, D.C.:  U.S. Department of Commerce.  Economic and Statistics Administration, U.S. Census Bureau, 2018.  Provides an overview of the ACS including information on the accuracy of estimates, how to access data, links to additional resources, etc.


The Who, What, and Where of America:  Understanding the American Community Survey.  Shana Hertz Hattis (editor). 9th Edition.  Lanham, Maryland:  Bernan Press, 2021.  Uses ACS data to provide of a sampling of key demographics to paint picture of the United States on various geographic levels.