# List of United States senators in the 31st Congress

This is a complete list of members of the United States Senate during the 31st United States Congress listed by seniority, from March 4, 1849, to March 3, 1851.
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 two-year congressional term (up until the last senator who was not sworn in early after winning the November 1850 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 3 | Terms of service of senators that expired in 1849 (AL, AR, CT, FL, GA, IA, IL, IN, KY, LA, MD, MO, NC, NH, NY, OH, PA, SC, VT, and WI.) |
| Class 1 | Terms of service of senators that expired in 1851 (CT, DE, FL, IN, MA, MD, ME, MI, MN, MO, MS, NJ, NY, OH, PA, RI, TN, TX, VA, VT, and WI.) |
| Class 2 | Terms of service of senators that expired in 1853 (AL, AR, DE, GA, IA, IL, KY, LA, MA, ME, MI, MS, NC, NH, NJ, RI, SC, TN, TX, and VA.) |

## U.S. Senate seniority list

U.S. Senate seniority :
| Rank | Senator (party-state) | Seniority date | Other factors |
| 1 | Thomas Hart Benton (D-MO) | August 10, 1821 | |
| 2 | Samuel Shethar Phelps (W-VT) | March 4, 1839 |
| 3 | Daniel Sturgeon (D-PA) | January 14, 1840 |
| 4 | Willie Person Mangum (W-NC) | November 25, 1840 |
| 5 | John Macpherson Berrien (W-GA) | March 4, 1841 | Former senator |
| 6 | Jacob Welsh Miller (W-NJ) | March 4, 1841 |
| 7 | William Lewis Dayton (W-NJ) | July 2, 1842 |
| 8 | James Alfred Pearce (W-MD) | March 4, 1843 | Former representative (6 years); Maryland 15th in population (1840) |
| 9 | William Upham (W-VT) | March 4, 1843 | |
| 10 | David Rice Atchison (R-MO) | October 14, 1843 | |
| 11 | Daniel Stevens Dickinson (D-NY) | November 30, 1844 |
| 12 | Daniel Webster (W-MA) | March 4, 1845 | Former senator (13 years) |
| 13 | Thomas Corwin (W-OH) | March 4, 1845 | Former representative (9 years) |
| 14 | Hopkins Lacy Turney (D-TN) | March 4, 1845 | Former representative (6 years) |
| 15 | Jesse D. Bright (D-IN) | March 4, 1845 | Indiana 10th in population (1840) |
| 16 | Reverdy Johnson (W-MD) | March 4, 1845 | Maryland 15th in population (1840) |
| 17 | Albert Collins Greene (W-RI) | March 4, 1845 | Rhode Island 24th in population (1840) |
| 18 | John Davis (W-MA) | March 24, 1845 |
| 19 | David Levy Yulee (D-FL) | July 1, 1845 | Former delegate |
| 20 | John Caldwell Calhoun (D-SC) | November 26, 1845 |
| 21 | Thomas Jefferson Rusk (D-TX) | February 21, 1846 | |
| 22 | Samuel Houston (D-TX) | February 26, 1846 | Former representative |
| 23 | George Edmund Badger (W-NC) | November 25, 1846 |
| 24 | Andrew Pickens Butler (D-SC) | December 4, 1846 |
| 25 | James M. Mason (D-VA) | January 21, 1847 |
| 26 | Robert M. T. Hunter (D-VA) | March 4, 1847 | Former representative (8 years); Virginia 4th in population (1840) |
| 27 | Joseph Rogers Underwood (W-KY) | March 4, 1847 | Former representative (8 years); Kentucky 6th in population (1840) |
| 28 | Stephen A. Douglas (D-IL) | March 4, 1847 | Former representative (4 years) |
| 29 | John P. Hale (FS-NH) | March 4, 1847 | Former representative (2 years) |
| 30 | Alpheus Felch (D-MI) | March 4, 1847 | Former governor |
| 31 | James Ware Bradbury (D-ME) | March 4, 1847 | Maine 13th in population (1840) |
| 32 | Henry Stuart Foote (D-MS) | March 4, 1847 | Mississippi 17th in population (1840) |
| 33 | Solomon Weathersbee Downs (D-LA) | March 4, 1847 | Louisiana 19th in population (1840) |
| 34 | John Hopkins Clarke (W-RI) | March 4, 1847 | Rhode Island 24th in population (1840) |
| 35 | Presley Spruance (W-DE) | March 4, 1847 | Delaware 26th in population (1840) |
| 36 | Jefferson Davis (D-MS) | August 10, 1847 |
| 37 | Roger Sherman Baldwin (W-CT) | November 11, 1847 |
| 38 | John Bell (W-TN) | November 22, 1847 |
| 39 | Wyman Bradbury Seavy Moor (D-ME) | January 5, 1848 |
| 40 | Solon Borland (D-AR) | March 30, 1848 |
| 41 | William K. Sebastian (D-AR) | May 12, 1848 |
| 42 | Hannibal Hamlin (D-ME) | June 8, 1848 | Former representative (4 years); Maine 13th in population (1840) |
| 43 | Henry Dodge (D-WI) | June 8, 1848 | Former delegate (4 years); Wisconsin 28th in population (1840) |
| 44 | Isaac Pigeon Walker (D-WI) | June 8, 1848 | Wisconsin 28th in population (1840) |
| 45 | William Rufus de Vane King (D-AL) | July 1, 1848 |
| 46 | Benjamin Fitzpatrick (D-AL) | November 25, 1848 |
| 47 | Augustus Caesar Dodge (D-IA) | December 7, 1848 | Former delegate (6 years) |
| 48 | George Wallace Jones (D-IA) | December 7, 1848 | Former delegate (3 years) |
| 49 | John Wales (W-DE) | February 23, 1849 |
| 50 | Lewis Cass (D-MI) | March 4, 1849 | Former senator |
| 51 | Salmon P. Chase (D-OH) | March 4, 1849 | |
| 52 | William Dawson (W-GA) | March 4, 1849 | |
| 53 | Jackson Morton (W-FL) | March 4, 1849 | |
| 54 | Moses Norris, Jr. (D-NH) | March 4, 1849 | |
| 55 | William H. Seward (W-NY) | March 4, 1849 | |
| 56 | Truman Smith (W-CT) | March 4, 1849 | |
| 57 | Pierre Soulé (D-LA) | March 4, 1849 | |
| 58 | James Whitcomb (D-IN) | March 4, 1849 | |
| 59 | James Cooper (W-PA) | March 4, 1849 | |
| | James Shields (D-IL) | October 27, 1849 |
| | Jeremiah Clemens (D-AL) | November 30, 1849 |
| | David Stewart (W-MA) | December 6, 1849 |
| | Thomas Pratt (D-MD) | January 12, 1850 |
| | Franklin Elmore (D-SC) | April 11, 1850 |
| | Robert Barnwell (D-SC) | June 4, 1850 |
| | Thomas Ewing (W-OH) | July 20, 1850 |
| | Robert Winthrop (W-MA) | July 22, 1850 |
| | John C. Frémont (R-CA) | September 9, 1850 |
| | William M. Gwin (D-CA) | September 9, 1850 | |
| | Robert Rhett (D-SC) | December 18, 1850 |
| | Robert Rantoul, Jr. (D-MA) | February 1, 1851 |