1866 United States elections

The 1866 United States elections occurred in the middle of National Union/Democratic President Andrew Johnson's term, during the Third Party System and Reconstruction. Johnson had become president on April 15, 1865, upon the death of his predecessor, Abraham Lincoln. Members of the 40th United States Congress were chosen in this election. As this was the first election after the Civil War, many ex-Confederates were barred from voting, and several Southern states did not take part in the election. Delegations from Arkansas, Florida, Alabama, North Carolina, Louisiana, and South Carolina were re-admitted during the 40th Congress.

1866 United States elections

← 1864          1865          1866          1867          1868 → Midterm elections
Incumbent president	Andrew Johnson (Democratic)[1]
Next Congress	40th
Senate elections
Overall control	Republican hold
Seats contested	25 of 66 seats[2]
Net seat change	Republican +2[3]
House elections
Overall control	Republican hold
Seats contested	All 224 voting seats
Net seat change	Republican +23[3]
1866 House of Representatives election results   Democratic seat   Republican seat   Independent seat

President Andrew Johnson held a National Union Convention in hopes of rallying supporters against the Radical Republicans. However, the Republican Party maintained a dominant majority in both houses of Congress, and ultimately impeached Johnson in 1868.

In the House, both parties picked up several seats, but Republicans retained a majority.[4]

In the Senate, Republicans won massive gains and increased their already-dominant majority, while Democrats suffered slight losses.[5]