Dorchester (colloquially referred to as Dot) is a historic neighborhood comprising more than 6 square miles in Boston, Massachusetts. Originally, Dorchester was a separate town, founded by Puritans who emigrated in 1630 from Dorchester, Dorset, England. The neighborhood is named after the town of Dorchester in the English county of Dorset, from which Puritans emigrated on the ship Mary and John, among others.