Hansen (who until his recent death taught English at the Univ. of the Pacific) compellingly tells the story of thousands of eager young Americans who volunteered to drive ambulances for the Allies in the Great War before the US army arrived in 1917. Hansen relates little-known stories of wealthy Americans sympathetic to the Allies, like H. Herman Harjes (a banker for J.P. Morgan), Boston Brahmin Richard Norton, and A. Piatt Andrew, a former Harvard professor and assistant secretary of the treasury, who led the way in forming private ambulance companies that raised money, recruited volunteers, and purchased or received donations of automobiles to convert into ambulances. As the author relates, they dealt with stubborn French military and government bureaucrats, frustrating delays, and personality conflicts while organizing medical services for the wounded in rear combat areas. But the volunteers, mostly from Ivy League colleges and eastern prep schools (as well as the likes of Ernest Hemingway and John Dos Passos), proved themselves and their state-of-the-art vehicles to be more effective than French horse-drawn ambulances, and they saved countless lives. Hansen has included many personal accounts of devotion to humanitarian efforts and many encounters with horror and heroism by the gallant gentlemen who faced the enemy shells and bullets on the Western Front. In time, Hansen tells us, the volunteers' ranks were augmented by a diverse group that included cowboys, big-game hunters, a Portuguese revolutionist, a racing car driver, and several football players. Women also played a significant role as doctors and nurses. Over 3,500 Americans had served as drivers when the US army took control of ambulance details on the Western Front in October 1917. A fitting tribute, told in effective matter-of-fact style, to mostly obscure volunteers who showed great bravery in a time of cataclysmic change and great tragedy.