A census is a "snapshot" of the entire population at a single point in time. The U.S. Census determines how many people reside within the country's borders, who they are, and where they live. Every 10 years since 1790, data from the decennial census have been used to apportion seats in the U.S. House of Representatives, as mandated by the U.S. constitution. With 860,000 temporary workers and a cost of $4.5 billion, the 2000 Census was the largest peacetime mobilization of resources and personnel by the federal government. The 2010 Census, which will take place next April, is projected to cost as much as $14 billion.
Why Is the Census Important?
In addition to reapportionment, U.S. courts determined in the 1960s that decennial census data should also be used to draw federal congressional and state legislative districts of equal population size—to ensure "one person, one vote." Each year, decennial census data are also used to allocate more than $400 billion in federal funds to state and local communities. Accurate census data are vital to other groups as well, such as teachers, journalists, social scientists, and businesses.