next term. | nowrap | |- ! | Israel Washburn Jr. | | Republican | 1850 | | Incumbent resigned January 1, 1861 to become Governor of Maine.New member elected November 6, 1860.Republican hold.Winner was not a candidate for election to the next term. | nowrap | |- ! | Silas M. Burroughs | | Republican | 1856 | | Incumbent died June 3, 1860.New member elected November 6, 1860.Republican hold. | nowrap | |} 37th Congress |- ! | Thomas Corwin | | Republican | 1858 | | Incumbent resigned March 12, 1861 to become U.S. Minister to Mexico.New member elected May 28, 1861.Unionist gain.Winner seated July 4, 1861. | nowrap | |- ! | John Sherman | | Republican | 1854 | | Incumbent resigned March 12, 1861 to become U.S. Senator.New member elected May 28, 1861.Republican hold.Winner seated July 4, 1861. | nowrap | |- ! | Charles F. Adams Sr. | | Republican | 1858 | | Incumbent resigned May 1, 1861 to become Ambassador to Great Britain.New member elected June 11, 1861.Unionist gain. | nowrap | |- ! | Edward Joy Morris | | Republican | 1856 | | Incumbent resigned June 8, 1861 to become U.S. Minister Resident to Turkey.New member elected June 21, 1861.Democratic gain.Winner seated July 2, 1861. | nowrap | |- ! | George W. Scranton | | Republican | 1858 | | Incumbent died March 24, 1861.New member elected June 21, 1861.Democratic gain.Winner seated July 4, 1861. | nowrap | |- ! | Samuel Curtis | | Republican | 1856 | | Incumbent resigned August 4, 1861 to become colonel of the 2nd Iowa Infantry.New member elected October 8, 1861.Republican hold. | nowrap | |- ! | John S. Carlile | | Unioinist | 1859 | | Incumbent resigned July 9, 1861 to become United States Senator from the loyal faction of Virginia.New member elected October 24, 1861.Unionist hold.Winner took his seat December 2, 1861. | nowrap | |- ! | William Appleton | | Constitutional Unioinist | 18501854 1860 | | Incumbent resigned September 27, 1861 due to failing health.New member elected November 5, 1861.Republican gain.Winner seated December 2, 1861. | nowrap | |- ! | John A. McClernand | | Democratic | 1859 | | Incumbent resigned October 28, 1861 to accept a commission as brigadier general of volunteers for service in the Civil War.New member elected December