Compared to events that occurred in the East, the American Revolutionary War in the West has received sparse attention despite its major impact on the geographical extent of the United States after the war. By 1779, the Americans, under George Rogers Clark, had wrested away most of the eastern side of the Mississippi River from the British. The same year, the Spanish, who controlled the western side of the Mississippi River, entered the war against the British. Orders were issued from the highest levels in Great Britain to sweep the Americans and Spanish from both sides of the Mississippi River. While coordinating several separate attacks, the centerpiece of the grand plan was the descent from the north by a huge British-led Indian contingent upon St. Louis and Cahokia, which suffered simultaneous attacks on May 26, 1780. This book covers not only those attacks and the entire British grand plan in detail, but also the Willing expedition; the Spanish conquests of Baton Rouge, Mobile, and Pensacola; the attack on Arkansas Post; the final peace treaties; the Louisiana Purchase; the uniforms of the combatants; and a biography of Fernando de Leyba – the defender of St. Louis.