New Jersey (1) | nowrap | John R. Thomson (D) | Died September 12, 1862.Successor was appointed. | nowrap | Richard S. Field (R) | November 21, 1862 |- | Oregon (2) | nowrap | Benjamin Stark (D) | Retired September 12, 1862, upon election of a successor. | nowrap | Benjamin F. Harding (D) | September 12, 1862 |- | Maryland (3) | nowrap | James Pearce (D) | Died December 20, 1862.Successor was appointed. | nowrap | Thomas H. Hicks (U) | December 29, 1862 |- | Indiana (1) | nowrap | Joseph A. Wright (U) | Retired January 14, 1863, upon election of a successor. | nowrap | David Turpie (D) | January 14, 1863 |- | New Jersey (1) | nowrap | Richard S. Field (R) | Retired January 14, 1863, upon election of a successor. | nowrap | James W. Wall (D) | January 14, 1863 |} House of Representatives |- | | colspan=2 | New seat. | nowrap | Hiram P. Bennett (Conservative R) | August 19, 1861 |- | | colspan=2 | New seat. | nowrap | John Cradlebaugh (I) | December 2, 1861 |- | | colspan=2 | New seat. | nowrap | John B. S. Todd (D) | December 9, 1861 |- | | colspan=2 | Vacant. | nowrap | Benjamin F. Flanders (U) | December 3, 1862 |- | | colspan=2 | Vacant. | nowrap | Michael Hahn (U) | December 3, 1862 |- | | Vacant | Representative-elect George W. Bridges was arrested by Confederate troops while en route to Washington, D.C. and held prisoner before he escaped. | nowrap | George W. Bridges (U) | February 25, 1863 |- | | colspan=2 | Vacant. | nowrap | Joseph E. Segar (U) | May 6, 1862 |- | | Vacant | Low not permitted to take seat, qualified later under special act of Congress, | nowrap | Frederick F. Low (R) | June 3, 1862 |- | | colspan=2 | Vacant. | nowrap | Charles H. Upton (U) | July 4, 1861 |- | | nowrap | Thomas Corwin (R) | Resigned March 12, 1861, to become Minister to Mexico. | nowrap | Richard A. Harrison (U) | July 4, 1861 |- | | nowrap | John Sherman (R) | Resigned March 12, 1861, when elected U.S. Senator. | nowrap | Samuel T. Worcester (R) | July 4, 1861