The Library of Congress has a complete archive of Congressional acts, but it is not necessarily presented in a single site.
One of the best "first stops" on such a topic is "Thomas," which is the site maintained by the Library of Congress for historical documents and legislative history:
the "Thomas" site. However, it's not going to do you much good unless you know what you are looking for and can conduct a rational search, or unless you are willing to just read page after page of the Congressional record.
Additionally, there is an on-line resource "clearing house" at the Law Library of Congress, which is also maintained by the Library of Congress, and which you can access at:
The Guide to Law On-line. In either case, you will need to know what you are looking for in order to conduct a useful search.