As the Civil War progressed both sides were willing to try new and unorthodox weapons systems. Witness the Monitor and the Virginia, two differently designed ironclads. Both of these designs were used later throughout the war. With their success both sides were willing to try new and different approaches to naval warfare.
Overall, there is enough information available for historians to surmise that there must have been more than 20 submarines, from both sides, developed throughout the American Civil War
The Confederacy had a robust program of building submarines. Their goal was to break the Union blockade along the East Coast and the Gulf Coast. There were “David” boats: long, narrow steamboats which ran awash with snorkel type smoke stacks and air intakes. These boats were largely ineffectual and not truly submarines.
They had William Cheeney who was based in Richmond and had his subs attempting attacks as early as 1861. He continued to work on producing improved subs throughout the Civil War.
In the summer of 1861 Cheeney’s first submarine was tested in the James River at Richmond. Here it successfully sank its target boat (an old barge). Reports of this test reached the north and caused much concern. The US navy began to develop anti-submarine measures right away. At first all they had was weighted nets and chains hanging around the ships in an effort to keep any sub from getting close enough to attach explosives to destroy the ship.
Cheeney developed a small three man submersible in the James River of Virginia in 1861 shortly after the outbreak of hostilities. A second, larger craft was developed by the same team and was similarly experimental. Cheeney’s craft were unsuccessful and were poorly documented although their existence was reported by Union spies.
In October of 1861 that primitive defense saved the USS Minnesota from being sunk. As Cheeney’s sub approached to attach explosives to the Minnesota, it got tangled in the defensive netting and its crew was barely able to get free and escape with their lives. That was the end of the first submarine attack of the Civil War.
The Bayou St. John Confederate Submarine is an early military submarine built for use by the Confederate States of America during the American Civil War. The submarine is constructed of riveted iron, 20 feet (6.1 m) long, 3 feet (0.91 m) wide and 6 feet (1.8 m) deep, with a hand-cranked propeller.
No period documentation for the submarine is known to exist, and its original name and many details about it remain unknown. The submarine was rediscovered in 1878 during a dredging of Bayou St. John at its intersection with Lake Pontchartrain in New Orleans, Louisiana, where the submarine was presumably scuttled to prevent it falling into Union hands after the U.S. capture of New Orleans.
Pioneer was the first of three submarines privately developed and paid for by Horace Lawson Hunley, James McClintock and Baxter Watson. They built Pioneer in New Orleans and was tested it in February 1862 in the Mississippi River. It was later towed to Lake Pontchartrain for additional trials, but the Union advance towards New Orleans the following month prompted the men to abandon development and scuttle Pioneer in the New Basin Canal. The team followed with the American Diver, built after relocating to Mobile, Alabama.
American Diver, also known as the Pioneer II, was a prototype submarine built for the Confederate States of America military. It was the first successor to the Pioneer. The Diver was invented and built by the same consortium that built the Pioneer in New Orleans. It was composed of Horace Lawson Hunley, James McClintock, and Baxter Watson.
They were forced to move their operations to Mobile, Alabama following the capture of New Orleans by Union forces in April 1862. Although ultimately unsuccessful, it served as a model in the development of the consortium’s next submarine, the H. L. Hunley. The Hunley eventually became the first combat submarine to sink an enemy warship.
The other well-known Confederate submarine was the C.S.S. Hunley. The Hunley was named for its builder Horace Lawson Hunley. It was built in Mobile, Alabama and was then shipped by rail on August 12, 1863, to Charleston, South Carolina. to break the Union blockade.
The Hunley (then called Fish Boat) sank on August 29, 1863, during a test run, killing five members of her crew. She sank again on October 15, 1863, killing all eight of her second crew, including Horace Hunley himself, who was aboard at the time, even though he was not a member of the Confederate militia. Both times the Hunley was raised and returned to service.
On February 17, 1864, The Hunley attacked and sank the 1240-short ton (1124 metric tons) screw sloop USS Housatonic, which had been on Union blockade-duty in Charleston’s outer harbor. Soon afterwards, the Hunley sank, killing all eight of her third crew. This time, the innovative ship was lost and not rediscovered until 1995. It was raised again in 2000.