Lesson 4: Census and Apportionment

Grades 9–12

Strand: Managing Data

Skills and Objectives

  • bullet Understand and describe the role census data play in apportionment decisions
  • bullet Discover how census data are used to uphold the principle of “one person, one vote”
  • bullet Analyze the connection between apportionment and the Electoral College

Materials: Census and Apportionment Student Worksheet 4, copy of the U.S. Constitution

Time Required: One 40-minute class period

    Getting Started

  1. Remind students that the census provides a count of people for the purpose of apportionment. Read aloud the following facts about apportionment:
    • The Constitution provides that each state will have a minimum of one member in the House of Representatives.
    • Between 1790 and 1910, the number of seats in the House was increased to accommodate a growing population.
    • The size of the House was capped by Congress at 435 seats following the 1910 Census; it can only be increased by an Act of Congress.
  2. Tell students that one of the main reasons for conducting the decennial census and keeping track of population changes is to accurately apportion the membership of the House of Representatives among the 50 states.
  3. Explain that, following a census, seats in the House of Representatives are automatically reapportioned according to the census data. In the past, Congress had to pass a bill for apportionment to take place. However, in 1929, 1940, and 1941, a series of acts were passed to allow for automatic apportionment so that census data would be used to realign the number of seats allocated to each state. If a state has gained population, it may receive additional seats. If a state has lost population, it may lose seats.
  4. Guide students to think about apportionment as being a tool for political equality. The principle of “one person, one vote” is a fundamental part of our democracy, and the apportionment process helps ensure that this principle is met. The biggest challenge with apportionment is ensuring that the 435 seats are divided fairly.
  5. Ask students to predict what they think might happen if their state were to gain or lose a seat in the House of Representatives. (Possible answers: The state would have more or less representation in Congress; the state would have to redraw its congressional districts.) Explain to students that while a state losing a seat may seem “unfair,” it is intended to accurately reflect population shifts throughout the whole country and ensure that proportional representation is maintained. Nevertheless, no state wants to lose seats, which is why local leaders urge residents to participate in the census.

    Using Student Worksheet 4
  6. Distribute copies of Census and Apportionment Student Worksheet 4. Review the map as a class. Point out to students that, in several states, the number of seats changed between 1990 and 2000. Guide students to recognize the shift in population from the north to the south. Point out that northern states such as New York lost up to two seats, while southern states such as Texas gained up to two seats. Ask students to theorize how this might have affected the House of Representatives.
  7. Instruct students to use the 1990/2000 apportionment map, as well as outside research, to project how the 2010 Census might affect the apportionment of House seats. Have students fill in the blank map with their projections.

  8. Explain to students that apportionment also affects presidential elections. In the Electoral College, each state has as many electors as it has representatives and senators in Congress. Add three votes for Washington, DC, and you reach the total number of presidential electors: 538.
  9. Ask students to think about how apportionment of House seats affects the Electoral College. To help explain the impact, ask students to look closely at their projection maps. Ask how the change in electors might influence how presidential candidates run their campaigns. (Possible answers: Candidates might spend more time in a particular section of the country that has had an increase in population; campaigns might put more money into advertising in states that have an increased number of electoral votes.)