Old Saybrook in the Revolution
David Bushnell's Turtle. Tier 2 - One sourced story.
Sourced Claims
[Verified] David Bushnell of nearby Westbrook (then part of Saybrook) built the Turtle - the first submarine used in combat - and tested it in the Connecticut River. - Connecticut State Library
[Tradition] The Turtle's 1776 attack on HMS Eagle in New York Harbor failed to attach its bomb, but it proved the concept of undersea warfare. - Smithsonian Institution