Who invented the first submarine?

In 1775, David Bushnell of Westbrook invented the first submarine near what is now Otter Cove in Old Saybrook. Built of oak beams, it resembled the shells of two turtles joined together and was called the American Turtle.
After successful trials on the river under the operation of Sergeant Ezra Lee of Lyme, the submarine was taken to New York. It made an unsuccessful attempt to destroy the H.M.S. Eagle of 64 guns, the flagship of the British fleet under Admiral Lord Howe. Two other attempts to sink British ships also ended in failure.

A replica of the submarine is on display at the Connecticut River Museum in Essex, CT.