As second captain of a gun on board the USS Lackawanna during successful attacks against Fort Morgan, rebel gunboats and the ram Tennessee in Mobile Bay, on 5 August 1864. Wounded when an enemy shell struck, Edwards refused to go below for aid and, as heavy return fire continued to strike his vessel, took the place of the first captain and carried out his duties during the prolonged action which resulted in the capture of the prize ram Tennessee and in the damaging and destruction of batteries at Fort Morgan.