The book explains how the Allies, after a series of swinging defeats, sank their differences and came together to turn the tide against the German Army in the Summer of 1918. Although it is a detailed history of the fighting by British divisions, it also highlights the growing presence of American forces and their huge contribution to victory, too often understated in earlier works. The book deliberately binds together the genesis, size and equipment of the British and American divisions and seeks to intermingle the American and British campaigns of 1918.