Edwin McMasters Stanton (December 19, 1814 – December 24, 1869), was an American lawyer, politician, United States Attorney General in 1860-61 and Secretary of War through most of the American Civil War and Reconstruction era.

Stanton was born in Steubenville, Ohio, the eldest of the four children of David and Lucy (Norman) Stanton. His father was a physician of Quaker stock. Stanton began his political life as a lawyer in Ohio and an antislavery Democrat. After graduating from Kenyon College in 1833, he was admitted to the Ohio bar in 1836. Stanton built a house in the small town of Cadiz, Ohio, and practiced law there until 1847, when he moved to Pittsburgh, Pennsylvania.

In 1856 Stanton moved to Washington, D.C., where he had a large practice before the Supreme Court. In 1859, Stanton was the defense attorney in the sensational trial of Daniel E. Sickles, a politician and later a Union general, who was tried on a charge of murdering his wife's lover (Philip Barton Key, son of Francis Scott Key), but was acquitted after Stanton invoked the first use of the insanity defense in U.S. history. In 1860 he was appointed as Attorney General by President James Buchanan. Although a staunch conservative Democrat, he strongly opposed secession, and is credited by historians for changing Buchanan's position away from tolerating secession to denouncing it as unconstitutional and illegal.

Stanton was politically opposed to Republican Abraham Lincoln in 1860 and referred to him as the "original gorilla". After Lincoln was elected president, Stanton agreed to work as a legal adviser to the inefficient Secretary of War, Simon Cameron, whom he replaced on January 15, 1862. He accepted the position only to "help save the country." He was very effective in administering the huge War Department, but he devoted considerable amounts of his energy to the persecution of Union officers whom he suspected of having traitorous sympathies for the South and the Civil War was a time of great political intrigue within the U.S. Army. The president recognized Stanton's ability, but whenever necessary Lincoln managed to "plow around him." Stanton once tried to fire the Chief of the War Department Telegraph Office, Thomas Eckert. Lincoln prevented this by defending Eckert and told Stanton he was doing a good job. This lead to Eckert keeping his job. Yet, when pressure was exerted to remove the unpopular secretary from office, Lincoln replied, "If you will find another secretary of war like him, I will gladly appoint him." Stanton became a Republican and changed his opinion of Lincoln. At Lincoln's death Stanton remarked, "Now he belongs to the ages," and lamented, "There lies the most perfect ruler of men the world has ever seen." He vigorously pursued the apprehension and prosecution of the conspirators involved in the assassination of President Lincoln. These proceedings were not handled by the civil courts, but by a military tribunal, and therefore under Stanton's tutelage. Stanton has subsequently been accused of witness tampering, most notably by Louis J. Weichmann, and of other activities that skewed the outcome of the trials.



Stanton continued to hold the position of secretary of war under President Andrew Johnson until 1868. His relations with the president were not good and Johnson attempted to remove Stanton from the Cabinet. Stanton, however, barricaded himself in his office, and the radicals in Congress, claiming that Johnson's actions violated the Tenure of Office Act, initiated impeachment proceedings against him. This was the primary count for which Johnson was impeached. After this Stanton resigned and returned to the practice of law. The next year he was appointed by President Grant to the Supreme Court, but he died four days after he was confirmed by the Senate, and before he could assume his seat. He died in Washington, D.C., and is buried there in Oak Hill Cemetery.

In the 1930s a book written by Otto Eisenschiml accused Stanton of arranging the assassination of Lincoln. Although these charges remain largely unsubstantiated, Eisenschim's book inspired considerable debate and the 1977 book and movie, The Lincoln Conspiracy.

Stanton College Preparatory School in Jacksonville, Florida is named in his honor.

One Dollar Treasury Notes, also called Coin Notes, of the Series' 1890 and 1891 feature portraits of Stanton on the obverse. Stanton also appears on the fourth issue of Fractional Currency, in the amount of 50 cents.