The United States Census Bureau is a bureau of the U.S. Department of Commerce. The major functions of the Census Bureau are authorized by Article 2, Section 2 of the United States Constitution, which provides that a census of population shall be taken every 10 years, and by Title 13 and Title 26 of the United States Code of Federal Regulations. The Census Bureau is responsible for numerous statistical programs, including census and surveys of households, governments, manufacturing and industries, and for U.S. foreign trade statistics. The first U.S. census was conducted in 1790 for the purposes of apportioning state representation in the U.S. House of Representatives and for the apportionment of taxes.

Reports the percentage of the voting-age, citizen population that voted in the November 6 election of the calendar year.

Information on reported voting and registration for the US population is collected for the nation biennially in November of congressional and presidential election years in the Current Population Survey (CPS). The CPS is a monthly survey of about 50,000 households conducted by the Bureau of the Census for the Bureau of Labor Statistics and is the primary source of information on the labor force characteristics of the US population. The voting supplement does not provide estimates of partisanship or party affiliation. People who are not US citizens are not eligible to vote. The voting-age population includes people who cannot register because they have been committed to the penal system, mental hospitals, or other institutions, or because they fail to meet state and local resident requirements for various reasons. The eligibility to register is governed by state laws. Over the years, changes have been made to the Voting and Registration supplement. The only constant is that in all iterations of the survey a separate question has been included regarding both voting and registration. The Voting and Registration supplement has remained relatively consistent since 1996. The "did not vote" category includes those who reported "did not vote" or "do not know," as well as noncitizens and nonrespondents.