On April 23, the first African-American women was made U.S. Attorney General: Democrat Loretta Lynch was nominated by Barack Obama late last year, and was now approved 56-43 by the U.S. Senate. Before her nomination, Lynch served as U.S. Attorney for the Eastern District of New York and has led succesful cases against police brutality, corruption and white-collar crimes.
Her predecessor, Eric Holder, was the first African-American man to become U.S. Attorney General. The first woman to hold the Position was Janet Reno, nominated by Bill Clinton in the 1990s.
The Department of Justice's and Eric Holder's Press release on the confirmation can be read here. A short profile on Loretta Lynch can be found here.