The lengthy and tense redistricting process is finally wrapping up, but anyone wanting a national map of congressional districts faces the tedious task of compiling them from each state — until now! We’re excited to share this year’s U.S. Congressional districts in a single place.

Our friends at Azavea have worked hard to track and compile this data from every state, and they graciously agreed to share this product of their Cicero API to be freely used by media, campaigns, and anyone else who has use for it.

(click to enlarge)

Why is this data so hard to come by, and why did it take until now to get it? Well, the US Constitution requires rebalancing representation between the states based on population shifts, making each district within a state just about equal in population. However, each state determines how to draw new district lines. To cut a long story short, each of the 43 states with at least two Representatives uses its own process and timeline to draw and approve the lines.

This dataset features the lines for the 2012 elections. You’ll note missing data for Kansas: the lines haven’t finalized there yet, and we’ll add that data once it’s available. Also, in several states there are ongoing court challenges - should a court order a review or a change of district lines, we’ll work to reflect those changes.

With several months to go until the general election, we hope that that members of the media, developers, and others trying to understand, explain, and advocate in this political cycle, can make good use of this data.

Posted by Jesse Friedman, Google Politics & Elections Team