The small garrison of a British outpost position, aided by Canadian reinforcements, fought off a large American attack.

Despite being outnumbered 12-1, the British pulled off the victory, due to their well-trained and high morale men defeating a non-experienced American group.

After the St. Lawrence campaign had ended late the previous year with the British victory at the Battle of Crysler's Farm, the defeated American Army under Major General James Wilkinson went into winter quarters at French Mills, New York, only just inside the United States.

Finally, in late January, Secretary of War John Armstrong ordered Wilkinson to detach a division numbering 2,000 men under Brigadier General Jacob Brown to Sackett's Harbor, New York, and fall back with the main body (about 4,000 fit men) to Plattsburgh, New York on Lake Champlain, while the sick and wounded were removed to Burlington, Vermont.

[9] British troops followed up almost to Plattsburgh, recovering large quantities of supplies from settlements in New York state such as Malone and Four Corners[10] and paroling many sick American soldiers who fell into their hands, before withdrawing.

Here, the British maintained an outpost of 80 men of the 13th Regiment of Foot in the Lacolle Mills Blockhouse and the stout stone-built watermill.

The defenders also included a Congreve rocket detachment of the Royal Marine Artillery, and there were other outpost positions and blockhouses nearby.

This was probably not a direct result of the debacle at Lacolle Mills, but followed a request made by Wilkinson himself on 24 March for a Court of Enquiry to rule on his conduct of the St. Lawrence campaign the previous year.

Major General George Izard, who had been on leave when the Battle of Lacolle Mills was fought, eventually took command at Plattsburgh.