Isaac Allerton Sr., and his family, were passengers in 1620 on the historic voyage of the ship Mayflower. Allerton was a signatory to the Mayflower Compact. In Plymouth Colony he was active in colony governmental affairs and business and later in trans-Atlantic trading. Problems with the latter regarding colony expenditures caused him to be censured by the colony government and ousted from the colony. He later became a well-to-do businessman elsewhere and in his later years resided in Connecticut.

Mayflower was an English sailing ship that transported a group of English families, known today as the Pilgrims, from England to the New World in 1620. After 10 weeks at sea, Mayflower, with 102 passengers and a crew of about 30, reached what is today the United States, dropping anchor near the tip of Cape Cod, Massachusetts, on November 21 [O.S. November 11], 1620.