The largest mass execution in the United States, of 38 Sioux Indians sentenced to death for engaging in massacres of American settlers, was carried out by hanging in Mankato, Minnesota in 1862. A total of 40 suspected Unionists were hanged in Gainesville, Texas in October 1862. On 7 July 1865, four people involved in the assassination of President Abraham Lincoln—Mary Surratt, Lewis Powell, David Herold, and George Atzerodt—were hanged at Fort McNair in Washington, D.C.