"Pittsburgh" gave continued service in the lengthy series of operations which wrested control of the lower Mississippi from the Confederacy. Her flotilla, previously under Army control, came under naval command October 1, 1862. Lieutenant Commander William R. Hoel USN took command of the Pittsburgh at this time. Highlights of her service were the operations against Plum Point Bend, Fort Pillow and Memphis in April, May and June 1862; the Steele's Bayou Expedition of March 1863; and the passing of the Vicksburg batteries April 16, 1863. She led the attack on the batteries at Grand Gulf on April 29 and was heavily damaged during the five-and-a-half-hour engagement. One of "Pittsburgh"s sailors, Boatswain's Mate John Woon, was awarded the Medal of Honor for his part in the battle. The action at Grand Gulf secured Union control of an important stretch of the river, making it possible for Grant to cross the river and attack Vicksburg from the rear. The strong Confederate river fortress surrendered July 4, allowing President Abraham Lincoln at last to report, "The Father of Waters flows unvexed to the sea."