The Congressional Record and its predecessors are the official record of the proceedings and debates of Congress.
Congressional Record via govinfo.gov
• Congressional Record (Daily) 1994 on (103rd Congress, 2nd Session- )
• History of Bills 1983-1984 on (98th Congress, 1st Session- )
• Congressional Record Index (Daily) 1983 on (98th Congress, 1st Session- )
• Congressional Record (Bound), March 1873 on (43rd Congress, Special Session- )
Congressional Record 1921 on via Congress.gov Library of Congress
The full-text of the predecessors to the Congressional Record is available through the Library of Congress' A Century of Lawmaking for a New Nation collection. Some of the early Congressional Record is also available on that site:
• Annals of Congress 1774-1824 (1st Congress - 18th Congress, 1st Session)
• Register of Debates 1824-1837 (18th Congress, 2nd Session - 25th Congress, 1st Session )
• Congressional Globe 1833-1873 (23rd - 42nd Congresses)
• Congressional Record 1873-1875 only (43rd Congress)