A map of all of the U.S. congressional districts (as of the 113th Congress). To find the district's number, look at the district, compare with the color code at the bottom to get number. The colors do not have any intrinsic meaning other than to provide visual distinction.
This file was derived from:

 US Congressional Districts color.svg: 
113th U.S. Congress House districts blank.svg:
US Congressional Districts color.svg: Mr. Matté
113th U.S. Congress House districts blank.svg: Mr. Matté
derivative work: Magog the Ogre (if you'd like to make use of this image without attribution, message me on my talk page or email me and we can discuss it)