For Want of a Nail is an alternate history classic. The outcome of one battle in the American Revolution diverges from reality, and sparks an unstoppable chain of events which affects the history of the whole North American continent. In reality, the British general John Burgoyne, heavily outnumbered by American troops, surrendered his army to General Horatio Gates at the Battle of Saratoga in 1777, a major turning-point of the Revolution. Robert Sobel takes a step sideways and presents the alternative version: reinforcements arrive at Saratoga, Gates men flee, and Burgoyne is victorious. Rather than openly allying itself with the American rebels, France withdraws its support, as does Spain, and the colonies surrender. Those former rebels who refuse to live in the Confederation of North America established by the British leave their homes and settle in what becomes the United States of Mexico. From then on the two continental nations find themselves constant rivals, locked in military, political and economic conflict. Sobel provides a detailed, intricately documented insight into two warring powers that develop in such dramatically different ways from their shared origins.