... all black members of Congress were Republicans from the South.

Things changed quickly from 1900 to 1933, and from 1935 on, everything went "south" and the overwhelming majority of blacks in Congress were Democrats.

Congress Name State or Territory Party House/Senate
Service
41st (1869-1871)2 House, 1 Senate
41st (1869-1871) LONG, Jefferson Franklin 1 GA Republican House
41st (1869-1871) RAINEY, Joseph Hayne 2 SC Republican House
41st (1869-1871) REVELS, Hiram Rhodes 3 MS Republican Senate
42nd (1871-1873)5 House
42nd (1871-1873) DE LARGE, Robert Carlos 4 SC Republican House
42nd (1871-1873) ELLIOTT, Robert Brown SC Republican House
42nd (1871-1873) RAINEY, Joseph Hayne SC Republican House
42nd (1871-1873) TURNER, Benjamin Sterling AL Republican House
42nd (1871-1873) WALLS, Josiah Thomas 5 FL Republican House
43rd (1873-1875)7 House
43rd (1873-1875) CAIN, Richard Harvey SC Republican House
43rd (1873-1875) ELLIOTT, Robert Brown 6 SC Republican House
43rd (1873-1875) LYNCH, John Roy MS Republican House
43rd (1873-1875) RAINEY, Joseph Hayne SC Republican House
43rd (1873-1875) RANSIER, Alonzo Jacob SC Republican House
43rd (1873-1875) RAPIER, James Thomas AL Republican House
43rd (1873-1875) WALLS, Josiah Thomas FL Republican House
44th (1875-1877)7 House, 1 Senate
44th (1875-1877) BRUCE, Blanche Kelso MS Republican Senate
44th (1875-1877) HARALSON, Jeremiah AL Republican House
44th (1875-1877) HYMAN, John Adams NC Republican House
44th (1875-1877) LYNCH, John Roy MS Republican House
44th (1875-1877) NASH, Charles Edmund LA Republican House
44th (1875-1877) RAINEY, Joseph Hayne SC Republican House
44th (1875-1877) SMALLS, Robert SC Republican House
44th (1875-1877) WALLS, Josiah Thomas 7 FL Republican House
45th (1877-1879)3 House, 1 Senate
45th (1877-1879) BRUCE, Blanche Kelso MS Republican Senate
45th (1877-1879) CAIN, Richard Harvey SC Republican House
45th (1877-1879) RAINEY, Joseph Hayne SC Republican House
45th (1877-1879) SMALLS, Robert SC Republican House
46th (1879-1881)1 Senate
46th (1879-1881) BRUCE, Blanche Kelso MS Republican Senate
47th (1881-1883)2 House
47th (1881-1883) LYNCH, John Roy 8 MS Republican House
47th (1881-1883) SMALLS, Robert 9 SC Republican House
48th (1883-1885)2 House
48th (1883-1885) O'HARA, James Edward NC Republican House
48th (1883-1885) SMALLS, Robert 10 SC Republican House
49th (1885-1887)2 House
49th (1885-1887) O'HARA, James Edward NC Republican House
49th (1885-1887) SMALLS, Robert SC Republican House
51st (1889-1891)3 House
51st (1889-1891) CHEATHAM, Henry Plummer NC Republican House
51st (1889-1891) LANGSTON, John Mercer 11 VA Republican House
51st (1889-1891) MILLER, Thomas Ezekiel 12 SC Republican House
52nd (1891-1893)1 House
52nd (1891-1893) CHEATHAM, Henry Plummer NC Republican House
53rd (1893-1895)1 House
53rd (1893-1895) MURRAY, George Washington SC Republican House
54th (1895-1897)1 House
54th (1895-1897) MURRAY, George Washington 13 SC Republican House
55th (1897-1899)1 House
55th (1897-1899) WHITE, George Henry NC Republican House
56th (1899-1901)1 House
56th (1899-1901) WHITE, George Henry NC Republican House