At the wheel on board the USS Cayuga during the capture of Forts St. Philip and Jackson, and New Orleans, 24 and 25 April 1862. As his ship led the advance column toward the barrier and both forts opened fire simultaneously, striking the vessel from stem to stern, Parker conscientiously performed his duties throughout the action in which attempts by 3 rebel steamers to butt and board were thwarted, and the ships driven off. Eleven gunboats were successfully engaged and the enemy garrisons forced to surrender during this battle in which the Cayuga sustained 46 hits.