Edwin McMasters Stanton (December 19, 1814 – December 24, 1869) was an American lawyer and politician who served as the 27th United States secretary of war under U.S. president Abraham Lincoln during most of the American Civil War. Stanton's management helped organize the massive military resources of the North and guide the Union to victory. However, he was criticized by many Union generals, who perceived Stanton as overcautious and a micromanager.
After the assassination of Abraham Lincoln, Stanton remained as the secretary of war under the new president, Andrew Johnson, during the first years of the Reconstruction Era. He also organized the manhunt for Lincoln's assassin, John Wilkes Booth. Stanton opposed the lenient policies of Johnson towards the former Confederate States. Johnson's attempt to dismiss him ultimately led to Johnson being impeached by the Radical Republicans in the House of Representatives. Stanton returned to law after he retired as secretary. In 1869, he was nominated as an associate justice of the Supreme Court by Johnson's successor, Ulysses S. Grant, but died four days after his nomination was confirmed by the Senate.