The official US Census form, pictured o

Official U.S. Census form.

The official US Census form, pictured on March 18, 2010 in Washington, DC, is required to be filled out and returned to the US Government by April 1, 2010. The all-important US tally determines everything from the number of seats a district is entitled in the US Congress, to the amount of dollars jurisdictions are given for federal projects. The first census was taken in 1790, when the population of the country was less than the current population of Los Angeles — around four million. AFP PHOTO / Paul J. RICHARDS (Photo credit should read PAUL J. RICHARDS/AFP/Getty Images)