All too frequently this [militia versus U.S. Army] proved disastrous to our armies, and inflicted defeat on our brave troops and frustrated carefully prepared plans. In speaking of this, [Canadian writer] Auchinleck says :
"We contend that the conduct of the greater part of the American militia on this occasion*, may be fairly adduced as an additional proof that the war was far from being as popular as one party in Congress would fain have represented it. It is notorious that many of the Pennsylvania militia refused to cross into Canada, while others returned, after having crossed the line, on constitutional pretexts. The truth is, and American writers may blink it or explain it as they please, that the refusal to cross the border, on the plea of its being unconstitutional, was one of the factious dogmas of the war, preached by the disaffected of Massachusetts, who imagined, doubtless, that the doctrine might be very convenient in the event of war in that region. The Kentuckians marched anywhere, they had no scruples. Why? Because the war was popular with them and they laughed at the idea that it was unconstitutional to cross a river or an ideal frontier, in the service of their country."
*The battle of Queenstown Heights, in which Brock was killed, and which should have been a most decisive victory for our forces. [Source]