Editor’s Note: One of the most respected historians of the Civil War and Indian conflicts, Peter Cozzens has written 17 books and is now at work on the third volume of a trilogy about the Indian wars in the American West, the Old Northwest (America’s Heartland), and the Old Southwest (the Deep South). Portions of this essay appear in the second volume, Tecumseh and the Prophet: The Shawnee Brothers Who Defied a Nation, published last month by Knopf. Mr. Cozzens’ 2016 book, The Earth is Weeping: The Epic Story of the Indian Wars of the American West, won the Gilder Lehrman Prize for Military History and is the first volume in the trilogy, which will conclude with A Brutal Reckoning: Andrew Jackson, the Creek Indians, and the Epic War for the American South, projected for publication in 2023.