Answer:
Edwin M. Stanton
Step-by-step explanation:
Edwin M. Stanton was a politician who served as Secretary of War under the Lincoln administration. He was instrumental in leading the Union to victory. After Lincoln's death, Stanton remained as Secretary of War under Andrew Johnson. This led to conflict, as Stanton opposed the lenient policies of Johnson towards the Confederate states. Johnson tried to remove him, but this brought impeachment proceedings against Johnson from the Radical Republicans.