 In 1654, Pell's uncle Thomas signed a treaty with Chief Wampage, and other Siwanoy Indian tribal members, that granted him of tribal land, including all or part of the Bronx and land to the west along Long Island Sound in what is now Westchester County, extending west to the Hutchinson River and north to Mamaroneck.Thomas founded the town of Westchester at the head of navigation on Westchester Creek.On October 6, 1666, Richard Nicolls, governor of the Province of New York under the Duke of York, "gave, granted and confirmed to Thomas Pell, Gentleman, all the land purchased from the Indian proprietors and created the same into an entire enfranchised township and manor."