Its proximity to the ocean will always be the most significant part of Groton's history. The 19th-century shipyards along the Mystic River produced some of the country's finest clipper ships. Land along the Thames River today remains home to the country's oldest submarine base and to the General Dynamics Electric Boat corporation, where the world's first nuclear-powered submarine, USS Nautilus, was built and first set sail. Today Nautilus is permanently...