The Bureau of the Census initiated the American Community Survey (ACS) in 2005. It will revolutionize the use of census data by providing annual updates to statistics that in the past were collected only every 10 years. Statistics will be published for areas of 65,000 people or more every year. The Bureau of the Census will distribute data for areas of between 20,000 and 64,999 in "3-year period ... [Show full abstract] averages." The first 3 year average will appear in 2008 covering 2005–2007. Subsequent data will be issued annually for the following three year periods. (e.g., 2006–2008, 2007–2009) Statistics for areas smaller than 19,999 will be published in 5-year period averages, the first to be published in 2010 covering 2005–2009. Subsequent data to be issued annually will cover 2006–2010, 2007–20011, … This paper provides background information about ACS, similarities and differences between it and the decennial census, the interpretation of statistics based upon period averages, relationships among ACS and other Bureau of the Census Surveys, and the expected future of the survey.