Fort Lennox National Historic Site of Canada

Natural Wonders & Cultural Treasures

The American Invasion

American officer wearing an orange justaucorps, yellow breeches, long black boots, a black hat and holding a pike in his right hand.
American officer, between 1775 and 1776
© Parks Canada / Illustration by G.A.Embleton

Stimulated by their desire for independence, revolutionaries in the 13 American colonies declared war on Great Britain in 1775. A few months later, they occupied île aux Noix. General Schuyler used it as a base for the attack on Montreal. One year later, in reaction to the resistance encountered at Quebec City and the British counter-attack, the Americans retreated to the island, which provided them with a strategic refuge for their troops. Following their withdrawal from île aux Noix, the island became the southernmost British defensive position on the Richelieu.

Black and white drawing. There are military constructions in background. In the foreground, there are a big tree, tree men and some cows in a large field.
Ile aux Noix, late 18th century. In the background, the French defense works constructed in 1759 and the British blockhouses erected in 1776.
© National Archives of Canada / Capitaine Rudyard / C-40335

The British then considered the island to be a major frontier post, and decided to fortify it. The original intention was to adapt the remains of the French fortification to contain a small garrison. A few blockhouses were constructed in 1779, making the fort capable of resisting an attack. Then, from 1779 to 1782, they built a much more impressive fortification using the plans drawn up by Twiss, an engineer.

The border with the newly founded United States was to remain a source of conflict, with clashes erupting sporadically. Finally, the ongoing state of tension between England and its former colony was to build up into another full-blown war.