The United States Constitution requires that the U.S. Census be conducted every 10 years, which first occurred in 1790. The census was last completed in 2010. Participation in the census is required by law in Title 13 of the United States Code. Title 13 also states that personally identifiable information is private and the Census Bureau will never release it. Why is the 2020 census important? The results of the census will determine the number of seats for each state in the House of Representatives, which mirrors the number of delegates for each state in the Electoral College, for elections in 2022 to 2030.