At the start of the war a small number of officers and men left the service to join the Confederacy and formed the core of the Confederate Revenue Marine. Six cutters had been seized by Confederate forces while in Southern ports. The "Harriet Lane" was temporarily transferred to the Union Navy. President Abraham Lincoln requested the Navy to transfer a number of ships to the Revenue Cutter Service, however no records show if any were actually transferred. During the remainder of the war, Revenue cutters protected Northern shipping and assisted the Navy in blockading Southern ports. The cutter "Harriet Lane" fired the first shots of the Civil War from a ship. But in 1863, in a battle with the Confederate Army and Navy, the "Harriet Lane" was captured and nearly all the crew members were killed.