“Tools are of no value unless they are used” (Vergil Reed, assistant director, Bureau of the Census, December 29, 1941).

The year 2010 marked a watershed in the history of the United States census. In that year, the U.S. Census Bureau released the first 5-year American Community Survey (ACS) estimates designed to provide data comparable to those produced by the decennial census long form used for the 2000 Census and previous censuses. The advent of the ACS signaled a change in the methodology and design underlying the collection of detailed information on population and housing characteristics for the nation's communities—a responsibility that the Census Bureau had shouldered increasingly at the behest of data users since the 1890 Census. This change had potentially far-reaching consequences.