On February 29, 1952, Congress designated September 17 as Constitution Day and Citizenship Day. This day commemorates the signing of the U.S. Constitution on September 17, 1787, and recognizes all American citizens.
The framers of the Constitution of the United States chose the population to be the basis for sharing political power, not wealth or land. Thus, they included a mandatory count of the population every 10 years (decennial census) in the Constitution. Article I, Section 2 states: “Representatives and direct Taxes shall be apportioned among the several States which may be included within this Union, according to their respective Numbers….”
Use the resources and materials below to teach students about the U.S. Census Bureau and its role in the Constitution.
With this warm-up activity, students learn about apportionment by coloring a map—identifying states with the highest and lowest number of U.S. representatives based on the 2020 Census population count. Then, they see how their state’s apportionment number compares to nearby states.
Students can explore maps and visualizations on our state profile pages to get key population characteristics for their state and county. These data on race, Hispanic origin, and the voting-age population are used by states for “redistricting” to redraw the boundaries of their congressional and legislative districts.
Census in the Constitution
The U.S. Census counts every resident in the United States. It is mandated by Article I, Section 2 of the Constitution and takes place every 10 years.
Constitution Day and Citizenship Day: September 17, 2021
The 2019 American Community Survey estimated there were 306.5M citizens and 21.8M noncitizens in the U.S. About 277.9M citizens were born in the U.S.