These guides explain how U.S. congressional districts, the House and Senate, redistricting, and elections work, in plain language. Start here for the background behind the numbers on this site. To find your own district and representative, use the lookup on the home page.
Mid-decade redistricting is the redrawing of congressional district lines between the usual once-per-decade cycles. District maps are normally set after each census and used for about ten years, but they can change in between. This guide explains why mid-decade changes happen, what occurred in the 2025 and 2026 cycle, and what it means for your … Read more
The terms sound alike and both follow the census, so they are easy to confuse, but redistricting vs reapportionment describes two distinct steps. Reapportionment decides how many House seats each state gets. Redistricting decides where the district lines go inside each state. This guide explains each one, the order they happen in, and who is … Read more
An at-large congressional district is a district that covers an entire state and is represented by a single member of the U.S. House. In an at-large seat there are no internal district lines, because the whole state is the district. This guide explains which states have one, how at-large representation works, and why it exists. … Read more
Packing and cracking are the two techniques behind almost every gerrymander. Mapmakers use them to turn the same set of voters into a very different set of election results, simply by deciding where the district lines fall. This guide explains how each technique works, walks through a simple example, and shows how to recognize them. … Read more
Gerrymandering is the practice of drawing electoral district boundaries to give one group an advantage over another. The goal is to shape who wins by deciding in advance which voters are grouped together. In the United States the term applies to congressional districts and to state legislative districts. This guide covers where the word came … Read more
Every American who lives in one of the 50 states is represented by a member of the U.S. House of Representatives. Your representative is determined by which congressional district you live in, and finding them takes less than a minute. Step 1: Enter Your ZIP Code The quickest way to find your representative is to … Read more
Congressional district maps show the geographic boundaries of each House district in the United States. These boundaries determine which representative serves your area, which candidates appear on your ballot, and how your community is grouped for federal representation. All current maps reflect the redistricting that followed the 2020 Census. Finding Your State’s Congressional Map We … Read more
There are 435 congressional districts in the United States, each represented by one member of the U.S. House of Representatives. This number has remained fixed since 1913, when Congress passed legislation capping the House at 435 seats. The Permanent Apportionment Act of 1929 made this cap permanent. Congressional districts by state The 435 districts are … Read more
Every ten years, the United States goes through one of the most consequential and least understood processes in American democracy: congressional redistricting. This process determines which neighborhoods, cities, and communities are grouped together into congressional districts, and by extension, who represents them in Washington. What Is Redistricting? Redistricting is the process of redrawing the boundaries … Read more
Your congressional district is the area that a single member of the U.S. House represents. The district you live in determines who represents you in Congress, so it helps to know how districts are drawn and how they work. What Is a Congressional District? A congressional district is a specific geographic area within a state … Read more