In 1775, an American army invaded Canada to encourage the French-Canadian ""habitants"" (small farmers) to join the revolt and to deprive the British of a base for an attack on the colonies. Hatch, a retired clergyman and history buff, offers a narrative of all the skirmishes and hardships leading to the American defeat--but it hews so close to the events that it loses focus. (Learning that a reinforcement consisted of the 15th, 24th and 25th Mass. regiments commanded by John Paterson, John Greaton, and William Bond ""respectively,"" adds little but complications to the tale.) After Ethan Alien took Fort Ticonderoga, Richard Montgomery led an army up Lake Champlain and easily took Montreal. Benedict Arnold was to lead a second wing of the attack up the Kennebec River in Maine and on to Quebec. But Arnold found the trip twice as long as expected and far more difficult. Using the journals of the men in Arnold's force, Hatch weaves a clear picture of their privations in the swamps and snow (self-inoculated smallpox, portages over mountains, poor guides and equipment); finally ""the men were eating shoe leather, belts, cartridge pouches, shaving soap, lip salve, and pomatum."" When they finally reached Quebec, Montgomery was killed, Arnold was wounded, and the army disintegrated. The American forces retreated south in disorder and occasional disgrace--Butterfield's surrender was termed by John Adams ""the first stain upon American arms."" The narrative concludes with the defeat of Arnold's fleet at Valcour Island. We do see the brilliant, difficult Arnold plain: ""his towering ego and savage temper could leave festering wounds. A few, like Daniel Morgan, could face him down. Others. . . nursed their grievances in secret."" The campaign is graphically detailed, but unless one is familiar with fascines, gabions, radeaus, and bateaux, many will remain mysterious. This, then, is for Hatch's fellow Revolutionary-War enthusiasts, who will be grateful for every hard-won particular.