Answer:
By the time Andrew Johnson assumed the Presidency of the U.S., in 1865, Edwin Stanton still was the Secretary of War. Nonetheless, the relationship between them wasn’t good since the beginning.
Stanton openly disagreed in several of the decisions the new president was making in matters of treatment of the former Confederate states, lack of federal intervention in the affairs of Southern states, etc. And it was clear that Johnson didn’t want him as Secretary of War anymore, so he attempted to fire him.
However, the Congress, which highly supported Stanton, had passed the Tenure of Office Act, in 1867, to prevent such dismissal.
After a few attempts to remove him, it wasn’t until May 1868 that Stanton voluntarily resign as Secretary of War.
Step-by-step explanation: