Isaac Allerton (ăl´ərtən), c.1586–1659, Pilgrim settler in Plymouth Colony. Possibly a London tailor, he was a merchant in Leiden before going to America on the Mayflower. From 1626 to 1631, acting as the agent of Plymouth Colony, he was often in England. While there he bought up the rights of merchants in the enterprise and in 1630 secured a new patent for the colony. The terms of the new patent, however, were opposed by William Bradford and other colonists. Allerton was at best incompetent and ran up the debt, even if he was not—as his neighbors accused him of being—dishonest. He was personally a wealthy man. He probably left Plymouth Colony in 1631 and was later at Marblehead, at New Amsterdam, and in the New Haven colony.