Answer:
Hiram Revels and Blanche Kelso Bruce
Explanation:
In 1870 Hiram Revels of Mississippi became the first African American senator. Five years later Blanche K. Bruce of Mississippi took the oath of office and became the first African American to preside over the Senate and to serve a full term.
https://history.house.gov/Exhibitions-and-Publications/BAIC/Historical-Data/Black-American-Representatives-and-Senators-by-Congress/
