Congress.gov is the official source for federal legislative information, replacing Thomas. On the main page, the default search is for current legislation. You can change the pull-down menu on the left to "All Legislation." Enter your keywords, topic, e.g., "mental health," "child nutrition," etc. On the results page, use the facets on the left to limit your search to specific Congresses and legislation type, e.g., "Status of Legislation."