The United States Senate elections of 1862 and 1863 were elections during the American Civil War in which Republicans increased their control of the U.S. Senate. The Republican Party gained three seats, bringing their majority to two-thirds of the body. Also caucusing with them were Unionists and Unconditional Unionists, giving them a commanding majority. As this election was prior to ratification of the Seventeenth Amendment, senators were chosen by state legislatures.