According to "Fifteen Minutes of Shame", Miles Chatterbox Musket was the founder of Quahog. Miles had the bad habit of talking nonstop. On his voyage to America, he was thrown overboard by his crew for talking about what he would do when he got to the new world. A clam saved him from drowning and brought him to Rhode Island. They became friends until he also drove the clam to irritation with his talking. The clam snapped at him asking if he ever shut up. Miles considered shooting the clam in his sleep. The clam saw him, and left him. Miles ran to him, telling him he's sorry. Since then, he never spoke again and has remained on the beach, hoping the magic clam would one day return.
However, in the later episode "Peter's Progress", it was revealed that this account of the founding of Quahog was a myth.