List of former members of the United States House of Representatives (U) Number of years/terms representative/delegate has served Number of years/terms representative/delegate has served

| Representative | Years | State_ | Party | Lifespan |
|---|---|---|---|---|
| Oscar Underwood | 1895–1896 1897–1915 | Alabama | Democratic | 1862–1929 |
| Thomas R. Underwood | 1949–1951 | Kentucky | Democratic | 1898–1956 |
| Warner Underwood | 1855–1859 | Kentucky | American | 1808–1872 |
| Jolene Unsoeld | 1989–1995 | Washington | Democratic | 1931– |
| Jonathan T. Updegraff | 1879–1882 | Ohio | Republican | 1822–1882 |
| Thomas Updegraff | 1879–1883 1893–1899 | Iowa | Republican | 1834–1910 |
| Ralph E. Updike | 1925–1929 | Indiana | Republican | 1894–1953 |
| Charles Wentworth Upham | 1853–1855 | Massachusetts | Whig | 1802–1875 |
| George B. Upham | 1801–1803 | New Hampshire | Federalist | 1768–1848 |
| Jabez Upham | 1807–1810 | Massachusetts | Federalist | 1764–1811 |
| Nathaniel Upham | 1817–1823 | New Hampshire | Democratic-Republican | 1774–1829 |
| William D. Upshaw | 1919–1927 | Georgia | Democratic | 1866–1952 |
| Charles Upson | 1863–1869 | Michigan | Republican | 1821–1885 |
| Christopher C. Upson | 1879–1883 | Texas | Democratic | 1829–1902 |
| William H. Upson | 1869–1873 | Ohio | Republican | 1823–1910 |