In 1783, with the Revolutionary War nearly over, the American dream of an independent republic almost died at the hands of the army that fought for it. While Continental Army officers waited in camp at Newburgh, New York, for negotiators to end the conflict, their long-simmering frustration with Congress finally boiled over. Anger swept through the corps from the lieutenants to the generals. These men had had enough—enough of inedible rations, inadequate clothing and supplies, and, most important, years of foregoing pay. A coup was in the making. Even the British knew it. As one of their spies reported, military...