In November, 1919, James Wormley "Jack" Jones was appointed as a Special Agent of the Bureau and is believed by most to be the first African American Special Agent in the history of the FBI in general. At the time, the FBI was known as the Bureau Of Investigation. Born in the 1880's in Fort Monroe, Virginia, Jones spent most of his education years at Virgina Union University.
In 1905, he joined the Washington, D. C. metro Police where he served in several positions including motorcycle policeman and detective.
He joined the Army and in 1917 was commissioned a captain and assigned to the 368th Infantry, and was commander of Company F. In 1918 he was sent to France and commanded his company in the Argonne Sector and the Metz front. At the end of the war he returned to the D. C. Police.
Appointed as a Special Agent in 1919, he served in the NYO and Pittsburgh and infiltrated Black Nationalist groups suspected of subversion. He resigned in 1923, mainly as a result of his true identity as an Agent being exposed and his resulting ineffectiveness in undercover investigations. He died in 1958.
More can be found about the early African-American Agents at the FBI's website here:
source: The FBI; A Comprehensive Reference Guide" Oryx Press, 1999, Edited by Athan G. Theoharis with Tony G. Poveda, Susan Rosenfeld, and Richard Gid Powers