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.

Each Constitution Day gives us a chance to learn about and understand the importance of what our Founding Fathers envisioned for our country, one of those things being an accurate count of our nation’s people. 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….” 

Apportionment is the process of dividing the 435 memberships, or seats, in the U.S. House of Representatives among the 50 states based on the apportionment population counts from the decennial census. Article I, Section 2 of the U.S. Constitution requires that a census of the population be taken every 10 years to apportion seats in Congress. 

Teach about apportionment using these activities and resources:

These grade appropriate activities were designed specifically to teach students about Constitution Day and congressional apportionment. They will learn what apportionment is, how it works, why it's important and how it relates to the decennial census. Each has a teaching guide to help instruct the activity.
 

These warm-up activities can be used at various grade levels and are designed to give students a basic understanding of apportionment. They are great class-starters and only take a short amount of time to complete.
 

View these animated videos to learn how apportion works and to see the formular used to ensure equal representation for all. 
 

These visualizations show the number of congressional representatives apportioned to each state as a result of U.S. population counts from the 2010 and 2000 Censuses.