"Beginning with the Continental Congress in 1774, America's national legislative bodies have kept records of their proceedings. These documents record American history in the words of those who built our government. The links below bring together in an online format, the records and acts of Congress from the Continental Congress and Constitutional Convention through the 43rd Congress, including the first three volumes of the Congressional Record, 1873-75."
The link below finds a list of the sessions and dates of the first through the current Congress, 1789- present. The list is at the website of the U.S. Senate.
Since 1934, the first session of a Congress convenes on January 3rd of odd-numbered years and adjourns on January 3 the following odd-numbered year. (For example, the 116th Congress began January 3, 2019 and will adjourn January 3, 2021.)