Key Facts
- Duration
- September 17 – November 3, 1775
- Length of siege
- 47 days
- Besieging commander
- Brigadier General Richard Montgomery
- Fort Chambly fell
- October 18, 1775
- Montreal fell
- November 13, 1775 (without battle)
Strategic Narrative Overview
After failed preliminary operations in early September, Brigadier General Richard Montgomery established a formal siege around Fort St. Jean on September 17. Disease, poor weather, and supply difficulties hampered the besiegers, but mortar batteries eventually struck the fort's interior. The nearby Fort Chambly fell on October 18, cutting British supply lines. A relief force dispatched by General Guy Carleton from Montreal was turned back on October 30, removing the garrison's last hope.
01 / The Origins
During the American Revolutionary War, the Continental Army launched an invasion of the British province of Quebec in 1775, aiming to deny Britain a base for operations and potentially bring Canada into the American cause. Fort St. Jean, guarding the Richelieu River corridor leading north toward Montreal, was the primary British fortification standing in the American army's path and had to be taken before any advance could proceed.
03 / The Outcome
With relief blocked and a new battery opening fire, the fort's defenders surrendered on November 3, 1775. The capitulation cleared the Richelieu corridor, and Montgomery's army marched on Montreal, which fell without resistance on November 13. General Carleton escaped to Quebec City to organize its defences against the expected American assault, which came later that winter.
Belligerents & Mobilization Analysis
Side A
1 belligerent
Richard Montgomery.
Side B
1 belligerent
Guy Carleton.
Kinetic Engagement Axis
Scroll horizontally to view full axis. Events plotted relatively.