The Treaty of Easton establishes the first American Indian reservation, at Indian Mills, New Jersey, for the Lenape.

The Treaty of Easton was a colonial agreement in North America signed in October 1758 during the French and Indian War between British colonials and the chiefs of 13 Native American nations, representing tribes of the Iroquois, Lenape (Delaware), and Shawnee. Negotiations over more than a week were concluded on October 26, 1758, at a ceremony held in Easton, Pennsylvania between the British colonial governors of the provinces of Pennsylvania and New Jersey, and representatives of 13 Indian nations, including the Iroquois, who sent chiefs of three of their nations to ensure their continued domination of their Ohio Country region; the eastern and western Lenape (Delaware), represented by two chiefs and headmen; Shawnee and others. More than 500 Native Americans attended the outdoor ceremony, after lengthy negotiations to bring peace to the regions of Pennsylvania, New Jersey and the Ohio Country.

An American Indian reservation is an area of land held and governed by a Native American tribal nation officially recognized by the U.S. federal government. The reservation's government is autonomous but subject to regulations passed by the United States Congress, and is administered by the United States Bureau of Indian Affairs. It is not subject, however, to a state or local government of the U.S. state in which it is located. Some of the country's 574 federally recognized tribes govern more than one of the 326 Indian reservations in the United States, while some share reservations, and others have no reservation at all. Historical piecemeal land allocations under the Dawes Act facilitated sales to non–Native Americans, resulting in some reservations becoming severely fragmented, with pieces of tribal and privately held land being treated as separate enclaves. This intersection of private and public real estate creates significant administrative, political, and legal difficulties.

Indian Mills, formerly known as Brotherton, is an unincorporated community located within Shamong Township in Burlington County, in the U.S. state of New Jersey. It was the site of Brotherton Indian Reservation, the only Indian reservation in New Jersey and the first in America, founded for the Lenni Lenape tribe, some of whom were native to New Jersey's Washington Valley.