David Bushnell, Class of 1792, made his mark in the Revolution not as a spy but as an engineer and inventor. He developed the world’s first submarine, which he christened the Turtle, in order to plant bombs on the hulls of British ships. (Shown here is a 1976 replica at the Connecticut River Museum.) The one-person, pedal-powered vessel proved seaworthy, but its one attempt at sabotage in New York Harbor was a failure. Bushnell went on to command a unit of military engineers.