Question: did they use submarines in the civil war

Answer: Yes, During the American Civil War, the Union was the first to field a submarine. The French-designed Alligator was the first U.S. Navy sub and the first to feature compressed air (for air supply) and an air filtration system. It was the first submarine to carry a diver lock, which allowed a diver to plant electrically detonated mines on enemy ships. Initially hand-powered by oars, it was converted after 6 months to a screw propeller powered by a hand crank. With a crew of 20, it was larger than Confederate submarines. Alligator was 47 feet (14 m) long and about 4 feet (1.2 m) in diameter. It was lost in a storm off Cape Hatteras on April 1, 1863, while uncrewed and under tow to its first combat deployment at Charleston.