Blanche Kelso Bruce, the son of a black slave and a white plantation owner, was the first African-American to serve a full term in the U.S. Senate. Bruce was born into slavery in Virginia, but escaped at the start of the Civil War and made his way to Ohio, where he attended Oberlin College. After the Civil War he moved to Mississippi and got involved in local politics. In 1874, during the post-war Reconstruction Era, Bruce was elected by the Mississippi legislature to become one of the state's two U.S. senators. (While serving, Bruce became the first African American to preside over the Senate, on February 14, 1879.) When his term ended in 1881, Bruce was appointed by President James Garfield to the office of Register of the Treasury. As such, Bruce was the first African-American to be represented on U.S. currency. Bruce also served as the recorder of deeds for Washington, D.C., and again as the Register of the Treasury, where he served until his death in 1898.
The title of Register of the Treasury no longer exists. According to the website of the U.S. Department of the Treasury, the office became the Public Debt Service in 1919, which in turn became the Bureau of the Public Debt in 1940.