voice vote - A vote in which the Presiding Officer states the question, then asks those in favor and against to say "Yea" or "Nay," respectively, and announces the result according to his or her judgment. The names or numbers of Senators voting on each side are not recorded.
Congressional Sessions lists all Congresses and corresponding years - from 1789, when the 1st Congress met, through the current Congress.
You can access legislative information, by bill number or key words, from the THOMAS Web site. Information from the present back to the 93rd Congress (1973) is available on THOMAS.
For information on the Senate, Congress, the legislative process and the federal government, the Virtual Reference Desk is a good place to begin.