Thus closed a war in which little was nominally gained, but much in reality. By it, indeed, the United States consummated their independence, which hitherto, so far as regarded England at least, had not fully existed. In other words, the war of 1812, freed the popular mind in America, from a sort of provincial reverence for Great Britain. It also removed that dread of her military prowess which had descended from the revolutionary epoch, but which was wholly unbecoming a nation so vigorous as the United States had since become. It is not too much to say that the military spirit of the Republic, which has since shone with such brilliancy, had its birth in the war of 1812.
The early misfortunes of the war, considered in this light, were not without benefits. They forced the nation to put forth its whole strength, and thus developed a capacity, of the existence of which, even she had been ignorant. From that hour the United States took a prouder stand among the nations of the earth. From that hour her flag was respected. Source