Tools for Tracking Legislation
Congress.gov is the official source for federal legislative information.
THOMAS.gov is the search engine for legislation covering 1973 to present.
Congressional Record is the official record of the proceedings and debates of the United States Congress covering 1994 to present.
History of Bills lists legislative actions on bills that are reported in the Congressional Record covering 1983 to present.
OpenCongress aggregates official legislative information with news articles and blog posts. Be aware that the relevance of news articles and blog posts is not good for less popular members of the Senate or House of Representatives.