In 1761, at a boarding school in New England, a young Mohawk Indian named Joseph Brant first met Samuel Kirkland, the son of a colonial clergyman. They began a long and intense relationship that would redefine North America. For nearly fifty years, their lives intertwined, at first as close friends but later as bitter foes. Kirkland served American expansion as a missionary and agent, promoting Indian conversion and dispossession. Brant pursued an alternative future for the continent by defending an Indian borderland nestled between the British in Canada and the Americans, rather than divided by them. By telling their dramatic story, Alan Taylor illuminates the dual borders that consolidated the new American nation after the Revolution. By constricting Indians within reservation lines, the Americans sought to control their northern boundary with the British Empire, which lingered in Canada. The border became firm as thousands of settlers established farms, held as private property, all around the new reservations. This struggle also pitted the federal government against the leaders of New York, competing to control the lands and the Indians of the border country. They contended for the highest of stakes because the transformation of Indian land constructed the wealth and the power of states, nations, and empires in North America.