The first viable and deployed ''submersible'' Warship developed and launched by The United States Navy, was The USS ''Plunger'' in 1901. It's designs were based on another ''Plunger'' prototype in 1896 (which ultimately lead to the 1901 Model). The American Civil War of 1861-65, showed the need for true ''submersibles''. Most Major European Nations with Navies were launching refined versions of ''Ironclad'' Warships. Although the idea of a fully submersible vessel went back Centuries, no real viable and safe prototypes were developed. The late Confederate States Navy came very close with The ''Hunley'', as did The Union Navy with The ''Alligator''. In the 1890s, The US Navy invested both time and monies into several Programs designed to make viable, the first ''undersea'' Warship. The ''Plunger'' was the result of these endeavors. ''Plunger'' was slightly over 100-tons in the water (displaced). It was 65-feet in length with a 12-foot Beam (Height). The ''Plunger'' was also entirely plated iron (riveted). She could achieve 9-mph on the surface with a speed of 8-mph underwater. The ''Plunger'' was also revolutionary in that it was both diesel and electric generator powered. The ''Plunger'' could achieve 100-feet in dive depth and could remain submerged for several hours on billed air. (7) Crewman were needed. The living and working conditions were somewhat horrible, and was the need for better ''sanitary conditions''. US President Theodore Roosevelt toured ''Plunger'' in 1905 and approved of her usage in Naval Warfare. Retrofitted many times, ''Plunger'' saw no Combat Service, but was the first ''Submarine Trainer'' Ship in The US Navy. She also served as a platform for Torpedo Testing. She remained a Trainer until 1907m when she was decommissioned. She remained in Dock until 1913 when she was scrapped.