The American victory at Plattsburg gave the United States the absolute control of Lake Champlain; and this, reinforcing their similar control of Lake Erie, counterbalanced the British military advantages all along the Canadian frontier.  The British command of the sea, the destruction of Washington, and the occupation of Maine told heavily on the other side.  These three British advantages had been won while the mother country was fighting with her right hand tied behind her back; and in all the elements of warlike strength the British Empire was vastly superior to the United States.  Thus there cannot be the slightest doubt that if the British had been free to continue the war they must have triumphed.  But they were not free.  Europe was seething with the profound unrest that made her statesmen feel the volcano heaving under their every step during the portentous year between Napoleon’s abdication and return.  The mighty British Navy, the veteran British Army, could not now be sent across the sea in overwhelming force.  So American diplomacy eagerly seized this chance of profiting by British needs, and took such good advantage of them that the Treaty of Ghent, which ended the war on Christmas Eve, left the two opponents in much the same position towards each other as before.  Neither of the main reasons for which the Americans had fought their three campaigns was even mentioned in the articles.

The war had been an unmitigated curse to the motherland herself; and it brought the usual curses in its train all over the scene of action.  But some positive good came out of it as well, both in Canada and in the United States.

The benefits conferred on the United States could not be given in apter words than those used by Gallatin, who, as the finance minister during four presidential terms, saw quite enough of the seamy side to sober his opinions, and who, as a prominent member of the war party, shared the disappointed hopes of his colleagues about the conquest of Canada.  His opinion is, of course, that of a partisan.  But it contains much truth, for all that: 

The war has been productive of evil and of good; but I think the good preponderates.  It has laid the foundations of permanent taxes and military establishments, which the Republicans [as the anti-Federalist Democrats were then called] had deemed unfavorable to the happiness and free institutions of the country.  Under our former system we were becoming too selfish, too much attached exclusively to the acquisition of wealth, above all, too much confined in our political feelings to local and state objects.  The war has renewed the national feelings and character which the Revolution had given, and which were daily lessening.  The people are now more American.  They feel and act more as a nation.  And I hope that the permanency of the Union is thereby better secured.

Gallatin did not, of course, foresee that it would take a third conflict to finish what the Revolution had begun.  But this sequel only strengthens his argument.  For that Union which was born in the throes of the Revolution had to pass through its tumultuous youth in ‘1812’ before reaching full manhood by means of the Civil War.