Vacant . Vacant . Charles H. Upton (U), July 4, 1861 – February 27, 1862 Lewis McKenzie (U), from February 16, 1863 . Vacant . Vacant . William G. Brown Sr. (U) . John S. Carlile (U), until July 9, 1861 Jacob B. Blair (U), from December 2, 1861 . Kellian Whaley (U) . Vacant Wisconsin . John F. Potter (R) . Luther Hanchett (R), until November 24, 1862 Walter D. McIndoe (R), from January 26, 1863 . A. Scott Sloan (R) Non-voting members . Hiram P. Bennet (R), from August 19, 1861 . John B. S. Todd (D), from December 9, 1861 . Samuel G. Daily (R) . John Cradlebaugh (I), from December 2, 1861 . John S. Watts (R) . John M. Bernhisel (I) . William H. Wallace (R) Changes in membership The count below reflects changes from the beginning of this Congress. Senate |- | Missouri (3) | Vacant | Did not take seat until after Congress commenced. | nowrap | Waldo P. Johnson (D) | March 17, 1861 |- | Kansas (2) | Vacant | Election not recognized by US Senate. | nowrap | James H. Lane (R) | April 4, 1861 |- | Kansas (3) | Vacant | Election not recognized by the Senate. | nowrap | Samuel C. Pomeroy (R) | April 4, 1861 |- | Pennsylvania (1) | nowrap | Simon Cameron (R) | Resigned March 4, 1861, to become Secretary of War.Successor was elected. | nowrap | David Wilmot (R) | March 14, 1861 |- | North Carolina (2) | nowrap | Thomas Bragg (D) | Withdrew March 6, 1861; expelled later in 1861. | colspan=2 | Vacant thereafter |- | Ohio (3) | nowrap | Salmon P. Chase (R) | Resigned March 7, 1861, to become Secretary of the Treasury.Successor was elected. | nowrap | John Sherman (R) | March 21, 1861 |- | Texas (1) | nowrap | Louis T. Wigfall (D) | Withdrew March 23, 1861. | colspan=2 | Vacant thereafter |- | North Carolina (3) | nowrap | Thomas L. Clingman (D) | Withdrew March 28, 1861; expelled later in 1861. | colspan=2 | Vacant thereafter |- | Virginia (2) | nowrap | Robert M. T. Hunter (D) | Withdrew March 28, 1861, and later expelled for support of the rebellion.Successor was elected. | nowrap | John S. Carlile (U) | July 9, 1861 |- | Virginia (1)