The 1918 U.S. Senate election was held November 5, 1918 coinciding with the midpoint of Woodrow Wilson's second term as President of the United States. The Republican Party gained control with a slim 2-seat majority after picking up a net six seats. The change in control was particularly important, as it meant that the Republicans were in a position to deny entry of the United States into the League of Nations, the centerpiece of Wilson's post-war foreign policy. It was the first election in which all Class 2 senators were subject to direct election following the enactment of the Seventeenth Amendment, making them the final class under the old system.