In August 1918, the 339th regiment of the US Army-roughly 5,000 soldiers, most hailing from Michigan-sailed for Europe to fight in World War I. But instead of the Western Front, these troops were headed to Archangel, Russia, a vital port city 1,000 miles northeast of Moscow. There, in the frozen subarctic, amid the chaos of the Russian Civil War, one of the most extraordinary episodes of American history unfolded.