Entitled: "Sheridan and his generals" showing Generals Wesley Merritt, Philip Sheridan, George Crook, James William Forsyth, and George Armstrong Custer around a table examining a document. Philip Henry Sheridan (March 6, 1831 - August 5, 1888) was a career United States Army officer and a Union general in the American Civil War. General Grant transferred him from command of an infantry division in the Western Theater to lead the Cavalry Corps of the Army of the Potomac in the East. In 1864, he defeated Confederate forces in the Shenandoah Valley and his destruction of the economic infrastructure of the Valley was one of the first uses of scorched earth tactics in the war. In 1865, his cavalry pursued General Lee and was instrumental in forcing his surrender at Appomattox. Sheridan fought in later years in the Indian Wars of the Great Plains. Both as a soldier and private citizen, he was instrumental in the development and protection of Yellowstone National Park. In 1883, Sheridan was appointed general-in-chief of the U.S. Army. He suffered a series of massive heart attacks two months after sending his memoirs to the publisher. After his first heart attack, the U.S. Congress quickly passed legislation to promote him to general. He died of heart failure at the age of 57. Photographed by Alexander Gardner, January 2, 1865.