In 1775, Governor Guy Carleton returned to Canada after a four-year absence in England to discover that political unrest in the American colonies was at a fever pitch. Soon after, open warfare erupted in Massachusetts, quickly followed by a rebel invasion. Historian Gavin K. Watt explores the first two campaigns of the American Revolution through their impact on Canada and describes how a motley group of militia, American loyalists, and British regulars managed to defend Quebec and repel the invaders.