Bockus on the left of the skirmish line, which rested on the main road.
The enemy advanced in close column, about 200 strong, with an advance guard about 100 yards ahead of the main body.

On its approach to the boundary line it was ordered to move at the double, and the advance guard rushed across.

As soon as it was on Canadian soil, Lieut.-Col.
Chamberlin's men opened fire on the advance guard.

The fire was returned from the main column of attack, which was still within United States territory.

The conflict then became general.