The naval engagements of the American Civil War changed the foundations of naval warfare due to the first-time use of ironclads and submarines, and the introduction of newer and more powerful naval artillery.The first shots of the naval war were fired on April 13, 1861, during the Battle of Fort Sumter, by the Revenue Service cutter USRC Harriet Lane and the final on June 22, 1865, by the Confederate raider CSS Shenandoah, in the Bering Strait, more than two months after General Robert E. Lee's surrender of the Confederate Army.