Originally published in 1936.

Told through the eyes of primary character Langdon Towne, much of this novel centers around the exploits and character of Robert Rogers, the leader of Rogers' Rangers, who were a colonial force fighting with the British during the French and Indian War. Structurally, Northwest Passage is divided into halves. The first half is a carefully researched, day-by-day recreation of the raid by Rogers' Rangers on the Indian village at Saint-François-du-Lac, Quebec (or Saint Francis, to the Americans troops), a settlement of the Abenakis, an American Indian tribe. The second half of the novel covers Rogers' later life in London, England and Fort Michilimackinac, Michigan. Roberts' decision to cover the novel's material in two distinct halves followed the actual trajectory of Rogers' life.