The 6th United States Congress was the 6th meeting of the legislative branch of the United States federal government, consisting of the Senate and the House of Representatives. It initially met at Congress Hall in Philadelphia, Pennsylvania and then was the first congress to meet in the new Capitol Building in Washington, D.C.. Its term was from March 4, 1799, to March 4, 1801, during the last two years of John Adams's presidency. It was the last Congress of the 18th century and the first to convene in the 19th. The apportionment of seats in House of Representatives was based on the 1790 United States census. Both chambers had a Federalist majority. This was the last Congress in which the Federalist Party controlled the presidency or either chamber of Congress.

The 5th United States Congress was a meeting of the legislative branch of the United States federal government, consisting of the United States Senate and the United States House of Representatives. It met at Congress Hall in Philadelphia, Pennsylvania, from March 4, 1797, to March 4, 1799, during the first two years of John Adams' presidency. In the context of the Quasi-War with France, the Alien and Sedition Acts were passed by Congress. The Acts were overwhelmingly supported by the Federalists and mostly opposed by the Democratic-Republicans. Some Democratic-Republicans, such as Timothy Bloodworth, said they would support formally going to war against France but they opposed the Alien and Sedition Acts which Bloodworth and others believed were unconstitutional.