South Carolina, was promoted to the rank of first lieutenant and for his services in South Carolina was bre vetted major. He was transferred to the Army of the Potomac where he served as acting aide-de-camp and engineer officer on the staff of General McClellan during the Antietam campaign, September, 1802. He was made assistant inspector-general with the rank of lieutenant-colonel, United States volunteers, November 8, 1802; having been transferred to the Army of the Tennessee, he took part in Grant's campagin in northern Mississippi and against Vicksburg as assistant engineer and inspector-general of the army. He received promotion to captain, United States army, May 7, 1803. He was engaged on the staff of General Grant in the Chattanooga campaign and received promotion to brigadier-general of volunteers, October 31, 1803. For services at Missionary Ridge he was brevetted lieutenant-colonel, United States army, November 12, 1803, and was engineer of the force sent to relieve Burnside at Knoxville.
He was then transferred to Washington, District of Columbia, as chief of the cavalry bureau; and when the cavalry of the Army of the Potomac was reorganized under Sheridan, he was placed in command of the third division. He was breve tted colonel, United States army, for his action in the battle of the Wilderness, March and 7, 1804. On May 8, 1804, he took possession of Spottsylvania Court House, Virginia, and was with Sheridan in his celebrated raid of May and June, 1804. He also led his division of cavalry at Beaver Dam, Yellow Tavern and Hawes Shop, and reinforced by Kautz's division, he commanded the combined force in its operations against the Danville and South Side Railroads during which he had several engagements, and destroyed all Confederate connection with the South for six weeks. He then rejoined Sheridan who had been assigned to the command of the Army of the Shenandoah and led his division at Opequan, September 19, 1804; and in October, 1804, was transferred to the Southwest and placed in command of the cavalry corps of the military division of the Mississippi.
He commanded the reorganized cavalry corps at Franklin, Tennessee, November 20, 1804, and at Nashville, December 15 and 16, 1864. In this battle he turned Hood's left and contributed greatly to his defeat. For his services he was brevetted brigadier-general, United States army, March 13, 1805. He led three divisions of his cavalry, 14,000 strong, through Alabama and Georgia defeating
