The 66th United States Congress was a meeting of the legislative branch of the United States federal government, comprising the United States Senate and the United States House of Representatives. It met in Washington, D.C., from March 4, 1919, to March 4, 1921, during the last two years of Woodrow Wilson's presidency. The apportionment of seats in the House of Representatives was based on the 1910 United States census.

The 65th United States Congress was a meeting of the legislative branch of the United States federal government, composed of the United States Senate and the United States House of Representatives. It met in Washington, D.C., from March 4, 1917, to March 4, 1919, during the fifth and sixth years of Woodrow Wilson's presidency. The apportionment of seats in this House of Representatives was based on the 1910 United States census.