File:Turtle submarine 1776.jpg. Retrieved November 20, 2018 from Wikimedia Commons https://commons.wikimedia.org/wiki/File:Turtle_submarine_1776.jpg
David Bushnell (1742-1824) graduated from Yale in 1775 at the beginning of the American Revolutionary War. Bushnell designed and built the first submarine, a turtle-shaped vessel propelled under water by a single operator.