Siege of Fort St. Jean

The Siege of Fort St. Jean was the first major action of the American invasion of Canada and opened the path to Montreal. Fort St. Jean was strategically positioned at the head of the Richelieu River where it emptied from Lake Champlain — the gateway to the St. Lawrence Valley and the road to Montreal and Quebec.

Montgomery commanded about 1,700 men and began siege operations on September 17. The British garrison of about 500 under Major Preston made a determined defense, hoping that relief would arrive from Montreal. Montgomery's siege was hampered by weather, disease, supply shortages, and the chronic discipline problems of colonial forces. Despite these difficulties, his engineers steadily pushed their trenches forward.

After six weeks of siege operations and the capture of a small British relief vessel on the lake, the garrison's position became hopeless. Preston surrendered on November 2 with about 500 men. The victory opened the path to Montreal and gave the Americans significant momentum in the Canadian campaign. Montreal fell shortly after without a fight when Carleton abandoned it to concentrate at Quebec City. The fall of Fort St. Jean represented the high-water mark of American strategic planning for the Canadian campaign.