Warpaths begins with the establishment of New France on the St Lawrence; through the colonists' War of Independence with the six years of fighting which ended with an English defeat at Yorktown; the civil war over the constitution of the United States in 1861 and the battle at Little Big Horn. Keegan also examines the final twist in the story of European warfare in North America, as American and Canadian forces arrive to save Britain and liberate France from domination by Germany in World War II.