On April 14, 1865, Abraham Lincoln, the 16th president of the United States, was assassinated by well-known stage actor John Wilkes Booth, while attending the play Our American Cousin at Ford's Theatre in Washington, D.C. Shot in the head as he watched the play, Lincoln died the following day at 7:22 am in the Petersen House opposite the theater. He was the first president to be assassinated, with his funeral and burial marking an extended period of national mourning.

Occurring near the end of the American Civil War, Lincoln's assassination was part of a larger conspiracy intended by Booth to revive the Confederate cause by eliminating the three most important officials of the federal government. Conspirators Lewis Powell and David Herold were assigned to kill Secretary of State William H. Seward, and George Atzerodt was tasked with killing Vice President Andrew Johnson. Beyond Lincoln's death, the plot failed: Seward was only wounded, and Johnson's would-be attacker became drunk instead of killing the vice president. After a dramatic initial escape, Booth was killed at the climax of a twelve-day chase. Powell, Herold, Atzerodt, and Mary Surratt were later hanged for their roles in the conspiracy.