Census takers are working to complete the 2010 Census, visiting households that did not return their census forms in April.
This is the 23rd time residents of the United States will have been counted, as required by Article One of the U.S. Constitution.
The first census was conducted in 1790. It took federal marshals 18 months to count just under 4 million people.
The job is much bigger today — the current census is projected to count just over 309 million. And, the law mandates that the results must be reported to the president by December 31st of this year. The most recent census, taken in 2000, counted nearly 281.5 million residents of the U.S.
Profile America is produced by the Public Information Office of the U.S. Census Bureau.