Are you looking for Congressional reports or hearings before 1970? Congressional Universe has just added a combined index to all these documents in a special file called "Congressional Indexes."

You can search by subject, committee, witness, or bill number, and the search form allows you to limit your search by a range of years between 1789 and 1972 or by a specific Congress. This combined index is equivalent to the printed CIS indexes of the Serial Set (Congressional reports and prints) and of Congressional hearings, both published and unpublished. The documents do not appear online in full text, but the citations refer you to the microfiche sets published by CIS. You can find the supporting microfiche at Mudd Library, but the Law Library also owns bound copies of most reports and published hearings from the 1930s to the early 1970s. For more information on how to find these hearings see this handy guide or ask at the Reference Desk.

You can access Congressional Indexes from the Congressional Universe link on the Research Databases page of the Law Library's website. Of course, Congressional Universe also contains indexing (and some full-text documents) for Congressional documents from 1970 to the present.