Learning that Lincoln was to attend Laura Keene's acclaimed performance of "Our American Cousin" at Ford's Theatre in Washington, D.C., on April 14, Booth—himself a well-known actor at the time—masterminded the simultaneous assassination of Lincoln, Vice President Andrew Johnson and Secretary of State William H. Seward. By murdering the president and two of his possible successors, Booth and his co-conspirators hoped to throw the U.S. government into disarray.
Lincoln occupied a private box above the stage with his wife Mary, a young army officer named Henry Rathbone and Rathbone’s fiancé, Clara Harris, the daughter of New York Senator Ira Harris. The Lincolns arrived late for the comedy, but the president was reportedly in a fine mood and laughed heartily during the production.
At 10:15, Booth slipped into the box and fired his .44-caliber single-shot derringer into the back of Lincoln's head. After stabbing Rathbone, who immediately rushed at him, in the shoulder, Booth leapt onto the stage and shouted, "Sic semper tyrannis!" ("Thus ever to tyrants!"–the Virginia state motto). At first, the crowd interpreted the unfolding drama as part of the production, but a scream from the first lady told them otherwise. Although Booth broke his leg in the fall, he managed to leave the theater and escape from Washington on