From their inaugural sessions, the United States Senate and House of Representatives have kept a journal of their proceedings in accordance with Article I, Section 5 of the Constitution, which provides that:
Each House shall keep a journal of its proceedings, and from time to time publish the same, excepting such parts as may in their judgment require secrecy; and the yeas and nays of the members of either House, on any question, shall, at the desire of one-fifth of those present, be entered on the journal.
The Journal should be seen as the minutes of floor action. It notes the matters considered and the votes and other actions taken. It does not record the actual debates.
Source: American Memory.