Cornplanter, a Seneca war chief and diplomat of the late eighteenth and early nineteenth centuries, negotiated repeatedly with the young United States and was granted, in return, a personal tract of land along the Allegheny River straddling the Pennsylvania and New York border, one of the few instances of an individual Haudenosaunee leader receiving land in his own name rather than through a nation's treaty. He was a half brother of Handsome Lake, the Seneca prophet who reformed the Longhouse religion, and the two men's shared origin at the village of Ganawagus ties Cornplanter's political career to the religious history his brother made. Thomas Abler's academic biography of Cornplanter is the standard published account of his life and of the grant that carried his name for a century and a half afterward.
In the 1960s the United States Army Corps of Engineers built the Kinzua Dam on the Allegheny River, and the reservoir it created flooded the entire Cornplanter Grant along with roughly ten thousand acres of the Seneca Nation's own Allegany Reservation, despite the 1794 Treaty of Canandaigua's promise that the land would remain Seneca in perpetuity. The flooding destroyed the Cold Spring Longhouse, a spiritual center for traditional Seneca religious practice, and displaced hundreds of Seneca families; in 1964, as the waters rose, engineers relocated Cornplanter's own grave and those of more than three hundred of his descendants and followers from a cemetery about to be submerged. The dam remains, for the Seneca Nation, a documented instance of a federally guaranteed treaty right overridden by a later federal project.