Apportionment and Redistricting Process for the U.S. House of Representatives

"The census, apportionment, and redistricting are interrelated activities that affect representation in the U.S. House of Representatives. Congressional apportionment (or reapportionment) is the process of dividing seats for the House among the 50 states following the decennial census. Redistricting refers to the process that follows, in which states create new congressional districts or redraw existing district boundaries to adjust for population changes and/or changes in the number of House seats for the state. At times, Congress has passed or considered legislation addressing apportionment and redistricting processes under its broad authority to make law affecting House elections under Article I, Section 4, of the U.S. Constitution. These processes are all rooted in provisions in Article I, Section 2 (as amen ded by Section 2 of the Fourteenth Amendment).

Seats for the House of Representatives are constitutionally required to be divided among the states, based on the population size of each state. To determine how many Representatives each state is entitled to, the Constitution requires the national population to be counted every 10 years, which is done through the census. The Constitution also limits the number of Representatives to no more than one for every 30,000 persons, provided that each state receives at least one Representative. Additional parameters for the census and for apportionment have been established through federal statutes, including timelines for these processes; the number of seats in the House; and the method by which House seats are divided among states. Congress began creating more permanent legislation by the early 20th century to provide recurring procedures for the census and apportionment, rather than passing measures each decade to address an upcoming reapportionment cycle. Federal law related to the census process is found in Title 13 of the U.S. Code, and two key statutes affecting apportionment today are the Permanent Apportionment Act of 1929 and the Apportionment Act of 1941..."
Apportionment and redistricting 

Apportionment and Redistricting Following the 2020 Census

"Updated April 27, 2021

The census, apportionment, and congressional redistricting are interrelated processes that occur every decade. The U.S. Constitution provides that a decennial census determines the distribution of U.S. House seats across states. Dividing House seats across states is known as apportionment (or reapportionment). Each state must receive one House seat and additional seats are distributed proportionally based on state population size. States then engage in redistricting, creating or redrawing geographic subdivisions with relatively equal-sized populations for each House district.

Timelines for the census and apportionment are provided in federal statute and generally occur as scheduled every decade. The Coronavirus Disease 2019 (COVID-19) pandemic, however, affected 2020 census field operations and delivery of apportionment figures, and concerns remain about timing for the redistricting processes that follow. This Insight provides background on the typical timing of the census, apportionment, and redistricting, as well as a brief discussion of recent census operational changes and proposals, particularly those related to congressional apportionment and redistricting.

Typical Timing—Census, Apportionment, and Redistricting
 
Figure 1 illustrates a timeline of the typical census, apportionment, and redistricting processes. Federal statute requires that April 1 of any year ending in “0” marks the official decennial census date. A count known as the apportionment population, which reflects the total resident population in each state, is typically used to distribute House seats. Within nine months of the decennial census date (December 31 of the year ending in “0”), the Secretary of Commerce is to report the apportionment population to the President; the Census Bureau has often released apportionment counts publicly at about the same time.

According to this timeline, within the first week of the first regular session of the next Congress, the President transmits a statement to Congress with information on how to apportion House seats. The President’s message contains the apportionment population and resulting number of Representatives for each state, based on the total number of Representatives (435) and using the method of equal proportions.

The Clerk of the House sends each governor a certificate indicating a state’s number of Representatives within 15 calendar days of receiving the President’s apportionment message. Each state receives the number of Representatives noted in the President’s statement, beginning at the start of the next session of Congress (typically, early January of a year ending in “3”). States may then engage in their own redistricting processes before the start of that Congress, and the timing of redistricting varies based on state laws..."
Apportionment and Redistricting 

The Amazing Apportionment Machine

"Apportionment is the process of dividing the seats in the House of Representatives among the 50 states based on the population figures collected during the decennial census. But how does it actually work? Through animation, the US Census Bureau helps explain how the apportionment formula is used to ensure equal representation for all, just like the Founding Fathers planned."

Apportionment Countdown
"2010 Census
Apportionment Countdown — Incorporate the 2010 Congressional Apportionment Countdown Clock into your website to help share the importance of census participation. The first data released from the 2010 Census are the official national and state population count, which are used to apportion seats in the U.S. House of Representatives. As mandated by the Constitution, this data must be delivered to the President of the United States on or before Dec. 31. For the apportionment widget, go to >..."

Apportionment Countdown
"2010 Census
Apportionment Countdown — Incorporate the 2010 Congressional Apportionment Countdown Clock into your website to help share the importance of census participation. The first data released from the 2010 Census are the official national and state population count, which are used to apportion seats in the U.S. House of Representatives. As mandated by the Constitution, this data must be delivered to the President of the United States on or before Dec. 31. For the apportionment widget, go to >..."