The Congress of the United States was created by Article I, section 1, of the Constitution, adopted by the Constitutional Convention on September 17, 1787, providing that "All legislative Powers herein granted shall be vested in a Congress of the United States, which shall consist of a Senate and House of Representatives."

The first Congress under the Constitution met on March 4, 1789,1 in the Federal Hall in New York City. The membership then consisted of 202 Senators and 59 Representatives.

The Senate is composed of 100 Members, 2 from each State, who are elected to serve for a term of 6 years. Senators were originally chosen by the State legislatures. This procedure was changed by the seventeenth amendment to the Constitution, adopted in 1913, which made the election of Senators a function of the people. One-third of the Senate is elected every 2 years.

1 North Carolina did not ratify the Constitution until November 21, 1789; Rhode Island on May 29, 1790.

New York ratified the Constitution on July 26, 1788, but did not elect its Senators until July 15 and 16, 1789.