Congress.gov is the official source for federal legislative information. It replaces the nearly 20-year-old THOMAS.gov site with a system that includes platform mobility, comprehensive information retrieval, and user-friendly presentation. It currently includes all data sets available on THOMAS.gov, except nominations, treaties and communications. THOMAS.gov was permanently retired at the end of 2014.

Language describing this source taken from: https://www.congress.gov/about