| Incumbent re-elected. | nowrap | |- | | James McLachlan | | Republican | 1900 | Incumbent re-elected. | nowrap | |- | | Milton J. Daniels | | Republican | 1902 | | Incumbent retired.New member elected.Republican hold. | nowrap | |} Colorado Connecticut Delaware Florida |- | | Stephen M. Sparkman | | Democratic | 1894 | Incumbent re-elected. | nowrap | |- | | Robert Wyche Davis | | Democratic | 1896 | | Incumbent retired.New member elected.Democratic hold. | nowrap | |- | | William B. Lamar | | Democratic | 1902 | Incumbent re-elected. | nowrap | |} Georgia Idaho |- ! | Burton L. French | | Republican | 1902 | Incumbent re-elected. | nowrap | |} Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland |- | | William H. Jackson | | Republican | 1900 | | Incumbent lost re-election. New member elected. Democratic gain. | nowrap | |- | | J. Frederick C. Talbott | | Democratic | 1902 | Incumbent re-elected. | nowrap | |- | | Frank C. Wachter | | Republican | 1898 | Incumbent re-elected. | nowrap | |- | | James W. Denny | | Democratic | 1902 | | Incumbent retired. New member elected. Democratic hold. | nowrap | |- | | Sydney Emanuel Mudd I | | Republican | 1896 | Incumbent re-elected. | nowrap | |- | | George A. Pearre | | Republican | 1898 | Incumbent re-elected. | nowrap | |} Massachusetts |- ! | George P. Lawrence | | Republican | 1897 (special) | Incumbent re-elected. | nowrap | |- ! | Frederick H. Gillett | | Republican | 1892 | Incumbent re-elected. | nowrap | |- ! | John R. Thayer | | Democratic | 1898 | | Incumbent retired.New member elected.Republican gain. | nowrap | |- ! | Charles Q. Tirrell | | Republican | 1900 | Incumbent re-elected. | nowrap | |- ! | Butler Ames | | Republican | 1902 | Incumbent re-elected. | nowrap | |- ! | Augustus Peabody Gardner | | Republican | 1902 (special) | Incumbent re-elected. | nowrap | |- ! | Ernest W. Roberts | | Republican | 1898 | Incumbent re-elected. | nowrap | |- ! | Samuel W. McCall | | Republican | 1892 | Incumbent re-elected. | nowrap | |- ! | John A. Keliher | |