In the United States, the census determines how certain money is distributed, how political lines are drawn and how the elected officials for the House of Representatives are distributed by state. The U.S. Census is compiled every 10 years as determined by the U.S. Constitution.
Before 1911, the number of representatives in the House of Representatives continued to grow as the population grew. However, Congress capped the number at 435 in 1911. Nonetheless, the census determines how those representatives are allocated by state.
The census also helps determine whether the amount of money allocated for a specific program is sufficient. For instance, because the census counts people by age, it helps determine how much money is needed for programs like Social Security and Medicare.