Although the U.S. Census Bureau carries out hundreds of surveys every year, its most well-known duty is still to conduct the decennial census. Census results have several high profile applications: they are used to reapportion seats in the House of Representatives, to realign congressional districts, and as a factor in the formulas that distribute trillions of dollars in federal funds each year. Because of the importance of this population count, procedural changes in the decennial census often reflect larger organizational shifts at the Census Bureau.

This section follows the evolution of the decennial census by detailing the events surrounding each of them. Political and technological changes, and the shifting public demand for information, have all shaped the modern census and the mission of the Census Bureau.