Foote led the squadron in the attack on Fort Donelson and then joined with Maj. Gen. John Pope's Army of the Mississippi for a joint attack on Island No. 10 on the Mississippi River. Charles H. Davis relieved Foote and proceeded to take Fort Pillow on the Mississippi. The U. S. Ram Fleet, commanded by Colonel Charles Ellet, Jr., accompanied the squadron during the Battle of Memphis. After the capture of Memphis the squadron was transferred to the control of the U.S. Navy. The transfer included the Ram Fleet, by then reconstituted as the Mississippi Marine Brigade. Davis aided Grant's unsuccessful first campaign against Vicksburg. Rear Admiral David D. Porter relieved Davis in command and led the squadron at Arkansas Post and during the successful Vicksburg Campaign and siege of the city.