Alfred Sully, a son of the painter Thomas Sully, was born in Philadelphia, on May 22, 1820. After his graduation from West Point in the class of 1841, he took part in the warfare against the Florida Seminoles and in the siege of Vera Cruz in 1847 during the Mexican War. He also served on frontier duty at a number of widely separated points and was operating against the rebellious Cheyennes when civil war broke out. Sully, after some preliminary duty in north Missouri and in the Washington defenses, was appointed colonel of the 1st Minnesota on March 4, 1862, and in the course of George B. McClellan's Peninsular campaign rose to brigade command in Sedgwick's division of the II Corps. He returned to command of his regiment at Sharpsburg, but was commissioned brigadier general of volunteers on September 26, 1862, and at Fredericksburg and in the campaign of Chancellorsville once again directed a brigade. Soon after the battle of Chancellorsville, Sully, who was perhaps more esteemed as an Indian fighter than as a brigade commander of infantry in the Army of the Potomac, was assigned to the command of the District of Dakota. In this position, under the nominal command of General John Pope, he executed a number of successful forays against the hostile Sioux in Minnesota and the Dakotas. Toward the close of the Civil War, Sully was brevetted major general of volunteers and brigadier general, U. S. Army. Upon muster out of the volunteer service he reverted to his regular rank of major of infantry, but was soon advanced to lieutenant colonel of the 3rd Infantry. In December, 1873, he became colonel of the 21st Infantry. Meanwhile, General Sully had discharged duty on the Indian frontier all over the West. During the last years of his life, his health permitting, he was intermittently in command of Fort Vancouver, Washington. He died there on April 27, 1879, and was buried ultimately in Laurel Hill Cemetery, Philadelphia.
Reference: Generals in Blue. Lives of the Union Commanders by Ezra J. Warner. Louisiana State University Press. Baton Rouge.