Who is Edwin M. Stanton from Reconstruction: America's Unfinished Revolution, 1863-1877 and what is their importance?

Edwin M. Stanton served as Secretary of War under both Presidents Lincoln and Johnson. He was in charge of overseeing the military control of Reconstruction. In the end, Stanton and Johnson's disagreements over policy led to his removal from office. The Republican-controlled Senate objected fiercely, leading Johnson to reinstate Stanton, but he was nevertheless impeached for his actions by the Senate.