You can use Congress.gov which is the official source for federal legislative information and materials on current and past legislation. From the choices on the top white menu bar, select Legislation and you will be able to search for all U.S. Congress legislation since 1973.
Other resources for current legislation include the following:
GovTrack.us GovTrack is a government transparency website. The site helps ordinary citizens find and track bills in the U.S. Congress and understand their representatives’ legislative record.
NexisUni US Bill Tracking (SBU ID required). Lets you search by a number of different fields and date ranges.
