# List of United States senators in the 16th Congress

This is a complete list of members of the United States Senate during the 16th United States Congress listed by seniority, from March 4, 1819, to March 3, 1821.
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.
The two main parties at this point were the Federalists (F), and Democratic Republicans (DR).

## Terms of service

| Class | Terms of service of senators that expired in years |
| Class 1 | Terms of service of senators that expired in 1827 (CT, DE, IN, MA, MD, ME, MS, NJ, NY, OH, PA, RI, TN, VA, and VT.) |
| Class 2 | Terms of service of senators that expired in 1829 (AL, DE, GA, IL, KY, LA, MA, ME, MS, NC, NH, NJ, RI, SC, and VA.) |
| Class 3 | Terms of service of senators that expired in 1831 (AL, CT, GA, IL, IN, KY, LA, MD, NC, NH, NY, OH, PA, SC, TN, and VT.) |

## U.S. Senate seniority list

U.S. Senate seniority :
| Rank | Senator (party-state) | Seniority date | Other factors |
| 1 | John Gaillard (DR-SC) | December 6, 1804 |
| 2 | Outerbridge Horsey (F-DE) | January 12, 1810 |
| 3 | Samuel Whittlesey Dana (F-CT) | December 4, 1810 |
| 4 | William Hunter (F-RI) | October 8, 1811 |
| 5 | Rufus King (F-NY) | March 4, 1813 |
| 6 | Jonathan Roberts (DR-PA) | February 24, 1814 |
| 7 | James Barbour (DR-VA) | January 2, 1815 |
| 8 | Isaac Tichenor (F-VT) | March 4, 1815 | Former senator |
| 9 | Nathan Sanford (DR-NY) | March 4, 1815 | New York 1st in population (1810) |
| 10 | James Jefferson Wilson (DR-NJ) | March 4, 1815 | New Jersey 12th in population (1810) |
| 11 | Benjamin Ruggles (DR-OH) | March 4, 1815 | Ohio 13th in population (1810) |
| 12 | John Williams (DR-TN) | October 10, 1815 |
| 13 | Nathaniel Macon (DR-NC) | December 5, 1815 |
| 14 | Montfort Stokes (DR-NC) | December 4, 1816 | North Carolina 4th in population (1810) |
| 15 | William Smith (DR-SC) | December 4, 1816 | South Carolina 6th in population (1810) |
| 16 | James Noble (DR-IN) | December 11, 1816 | Alphabetical (N) |
| 17 | Waller Taylor (DR-IN) | December 11, 1816 | Alphabetical (T) |
| 18 | Alexander Contee Hanson (F-MD) | December 20, 1816 |
| 19 | John Wayles Eppes (DR-VA) | March 4, 1817 | Former representative (10 years) |
| 20 | Harrison Gray Otis (F-MA) | March 4, 1817 | Former representative (4 years) |
| 21 | Nicholas Van Dyke (F-DE) | March 4, 1817 | Former representative (3 years, 4 months) |
| 22 | Mahlon Dickerson (DR-NJ) | March 4, 1817 | Former governor |
| 23 | David Lawrence Morril (DR-NH) | March 4, 1817 | New Hampshire 15th in population (1810) |
| 24 | James Burrill, Jr. (F-RI) | March 4, 1817 | Rhode Island 16th in population (1810) |
| 25 | Walter Leake (DR-MS) | December 10, 1817 | Alphabetical (L) |
| 26 | Thomas Hill Williams (DR-MS) | December 10, 1817 | Alphabetical (W) |
| 27 | Henry Johnson (DR-LA) | January 12, 1818 |
| 28 | Prentiss Mellen (F-MA) | June 5, 1818 |
| 29 | John Henry Eaton (DR-TN) | September 5, 1818 |
| 30 | William Adams Palmer (DR-VT) | October 20, 1818 |
| 31 | Jesse Burgess Thomas (DR-IL) | December 3, 1818 | Former delegate |
| 32 | Ninian Edwards (DR-IL) | December 3, 1818 |
| 33 | James Brown (DR-LA) | March 4, 1819 | Former senator |
| 34 | Edward Lloyd (DR-MD) | March 4, 1819 | Former representative (2 years, 3 months) |
| 35 | John Fabyan Parrott (DR-NH) | March 4, 1819 | Former representative (2 years, 0 months) |
| 36 | Walter Lowrie (DR-PA) | March 4, 1819 | Pennsylvania 3rd in population (1810) |
| 37 | William Logan (DR-KY) | March 4, 1819 | Kentucky 7th in population (1810) |
| 38 | James Lanman (DR-CT) | March 4, 1819 | Connecticut 9th in population (1810) |
| 39 | John Elliott (DR-GA) | March 4, 1819 | Georgia 11th in population (1810) |
| 40 | William Allen Trimble (DR-OH) | March 4, 1819 | Ohio 13th in population (1810) |
| 41 | Freeman Walker (DR-GA) | November 6, 1819 |
| 42 | Richard Mentor Johnson (DR-KY) | December 10, 1819 |
| 43 | James Pleasants (DR-VA) | December 14, 1819 | Former representative (8 years) |
| 44 | William Rufus de Vane King (DR-AL) | December 14, 1819 | Former representative (5 years) |
| 45 | John Williams Walker (DR-AL) | December 14, 1819 |
| 46 | William Pinkney (DR-MD) | December 21, 1819 |
| 47 | Elijah Hunt Mills (F-MA) | June 12, 1820 |
| 48 | John Holmes (DR-ME) | June 13, 1820 |
| 49 | John Chandler (DR-ME) | June 14, 1820 |
| 50 | David Holmes (DR-MS) | August 30, 1820 |
| 51 | Isham Talbot (DR-KY) | October 19, 1820 |
| 52 | Nehemiah Rice Knight (DR-RI) | January 9, 1821 |
| 53 | Samuel Lewis Southard (DR-NJ) | January 26, 1821 |