# List of United States senators in the 40th Congress

This is a complete list of members of the United States Senate during the 40th United States Congress listed by seniority, from March 4, 1867, to March 3, 1869.
Order of service is based on the commencement of the senator's first term. Behind this is former service as a senator (only giving the senator seniority within his or her new incoming class), service as vice president, a House member, a cabinet secretary, or a governor of a state. The final factor is the population of the senator's state.
Senators who were sworn in during the middle of the Congress (up until the last senator who was not sworn in early after winning the November 1868 election) are listed at the end of the list with no number.

## Terms of service

| Class | Terms of service of senators that expired in years |
| Class 1 | Terms of service of senators that expired in 1869 (CA, CT, DE, FL, IN, MA, MD, ME, MI, MN, MO, MS, MT, NE, NJ, NV, NY, OH, PA, RI, TN, TX, VA, VT, WI, and WV.) |
| Class 2 | Terms of service of senators that expired in 1871 (AL, AR, DE, GA, IA, IL, KS, KY, LA, MA, ME, MI, MN, MS, MT, NC, NE, NH, NJ, OR, RI, SC, TN, TX, VA, and WV.) |
| Class 3 | Terms of service of senators that expired in 1873 (AL, AR, CA, CT, FL, GA, IA, IL, IN, KS, KY, LA, MD, MO, NC, NH, NV, NY, OH, OR, PA, SC, VT, and WI.) |

## U.S. Senate seniority list

U.S. Senate seniority :
| Rank | Senator (party-state) | Seniority date | Other factors |
| 1 | Benjamin Wade (R-OH) | March 15, 1851 | |
| 2 | Charles Sumner (LR-MA) | April 11, 1851 | |
| 3 | Henry Wilson (R-MA) | January 31, 1855 | |
| 4 | Lyman Trumbull (R-IL) | March 4, 1855 | |
| 5 | Zachariah Chandler (R-MI) | March 4, 1857 | |
| 6 | James Dixon (R-CT) | March 4, 1857 | |
| 7 | James R. Doolittle (R-WI) | March 4, 1857 | |
| 8 | Henry B. Anthony (R-RI) | March 4, 1859 | Former governor |
| 9 | Willard Saulsbury, Sr. (D-DE) | March 4, 1859 | |
| 10 | James W. Grimes (R-IA) | March 4, 1859 | |
| 11 | Timothy O. Howe (R-WI) | March 4, 1861 | |
| 12 | John Sherman (R-OH) | March 21, 1861 | |
| 13 | Samuel C. Pomeroy (R-KS) | April 4, 1861 | |
| 14 | Garrett Davis (D-KY) | December 23, 1861 | |
| 15 | Jacob M. Howard (R-MI) | January 17, 1862 | |
| 16 | Alexander Ramsey (R-MN) | March 4, 1863 | |
| 17 | William Sprague IV (R-RI) | March 4, 1863 | |
| 18 | John Conness (R-CA) | March 4, 1863 | |
| 19 | Thomas A. Hendricks (D-IN) | March 4, 1863 | |
| 20 | Reverdy Johnson (D-MD) | March 4, 1863 | |
| 21 | Edwin D. Morgan (R-NY) | March 4, 1863 | |
| 22 | Charles R. Buckalew (D-PA) | March 4, 1863 | |
| 23 | Waitman T. Willey (R-VA) | August 4, 1863 | |
| 24 | Peter G. Van Winkle (R-WV) | August 4, 1863 | |
| 25 | George R. Riddle (D-DE) | February 2, 1864 | |
| 26 | William M. Stewart (R-NV) | February 1, 1865 | |
| 27 | James W. Nye (R-NV) | February 1, 1865 | |
| 28 | Aaron H. Cragin (R-NH) | March 4, 1865 | |
| 29 | Richard Yates (R-IL) | March 4, 1865 | |
| 30 | William P. Fessenden (R-ME) | March 4, 1865 | |
| 31 | Daniel S. Norton (R-MN) | March 4, 1865 | |
| 32 | George H. Williams (R-OR) | March 4, 1865 | |
| 33 | James Guthrie (D-KY) | March 4, 1865 | |
| 34 | George F. Edmunds (R-VT) | April 3, 1866 | |
| 35 | Edmund G. Ross (R-KS) | July 19, 1866 | |
| 36 | Joseph S. Fowler (R-TN) | July 24, 1866 | |
| 37 | David T. Patterson (R-TN) | July 28, 1866 | |
| 38 | Alexander G. Cattell (R-NJ) | September 19, 1866 | |
| 39 | Thomas Tipton (R-NE) | March 1, 1867 | |
| 40 | John Milton Thayer (R-NE) | March 1, 1867 | |
| 41 | Roscoe Conkling (R-NY) | March 4, 1867 | |
| 42 | Justin Smith Morrill (R-VT) | March 4, 1867 | |
| 43 | Oliver P. Morton (R-IN) | March 4, 1867 | |
| 44 | Simon Cameron (R-PA) | March 4, 1867 | |
| 45 | Orris S. Ferry (R-CT) | March 4, 1867 | |
| 46 | Cornelius Cole (R-CA) | March 4, 1867 | |
| 47 | James Harlan (R-IA) | March 4, 1867 | |
| 48 | James W. Patterson (R-NH) | March 4, 1867 | |
| 49 | Henry W. Corbett (R-OR) | March 4, 1867 | |
| 50 | Charles D. Drake (R-MO) | March 4, 1867 | |
| | James A. Bayard Jr. (D-DE) | April 5, 1867 | |
| | Thomas C. McCreery (D-KY) | February 19, 1868 | |
| | George Vickers (D-MD) | March 7, 1868 | |
| | Adonijah Welch (R-FL) | June 17, 1868 | |
| | Alexander McDonald (R-AR) | June 22, 1868 | |
| | Benjamin F. Rice (R-AR) | June 23, 1868 | |
| | Thomas W. Osborn (R-FL) | June 25, 1868 | |
| | John S. Harris (R-LA) | July 8, 1868 | |
| | William P. Kellogg (R-LA) | July 9, 1868 | |
| | George E. Spencer (R-AL) | July 13, 1868 | |
| | Willard Warner (R-AL) | July 13, 1868 | |
| | John Pool (R-NC) | July 14, 1868 | |
| | Joseph Carter Abbott (R-NC) | July 14, 1868 | |
| | Thomas J. Robertson (R-SC) | July 15, 1868 | |
| | Frederick A. Sawyer (R-SC) | July 16, 1868 | |