Who was the first African-American elected to the legislature of the U.S.?

The first African-American to enter the legislature of the United States was Hiram Rhodes Revels, a Republican from Mississippi. He entered the chamber of the Senate to take his oath of office in February of 1870. 

Revels was born free in North Carolina, but he lived and worked in Ohio, where he was able to vote before the Civil War. This last fact enabled him to serve as a Senator when racially-motivated Democrats argued that he had not met the nine-year citizenship requirement to hold congressional office because of his ineligibility through the war years. Revels and his Republican allies also prevailed by citing Revels's mixed-race background (his mother was of Scottish descent).

As a Senator, Revels naturally was most concerned about obtaining civil rights for African-Americans. However, he also took a moderate stance on the restoration of citizens' rights such as voting for former Confederates, and he urged radical Republicans to lessen punishments for Civil War rebels. Because of his diplomacy and oratorical skills, the press praised Senator Revels during his term.

Later, when an opportunity arose to become president and instructor of philosophy at Alcorn Agricultural and Mechanical College, located in Claiborne County, Mississippi, Revels accepted because the education and intellectual development of African-Americans was also an important cause of his.