The most recent geographic information sources from the Census Bureau are on their website. There are other online sources that offer data maps by congressional districts. Historical maps by congressional districts are found in print sources.
The following materials link to fuller bibliographic information in the Library of Congress Online Catalog. Links to additional online content are provided when available.
The subscription resources marked with a padlock are available to researchers on-site at the Library of Congress. If you are unable to visit the Library, you may be able to access these resources through your local public or academic library.