American idealism was asleep, but its slumbers were by no means sound. The voices of Garrison, Emerson and others mingled troublously with its dreams. And the pursuit and capture of fugitive slaves like Anthony Burns, in Boston itself; and the extraordinary sale, both in America and Europe, of _Uncle Tom's Cabin_,[142] did much to quicken that Abolitionist sentiment which in the end won the day. For the present, however, and until the third year of the war, abolition remained outside the region of practical politics. The question which was dividing the nation was whether slavery should become a national institution--whether it should take its place, as the South intended, as one of the essential postulates in the theory of American liberty--or should be restrained within its old limits as a State institution, an evil which the Federal Government would never recognise as necessary to the welfare of America, but which it was too proud and too generous to compel its constituent States to abolish. The situation was one of unstable equilibrium, and the illogical position could not much longer be maintained. It was the logic of ideas that first drove the South into secession, and afterwards the nation into abolition. * * * * * Immigration was now beginning to create a difficult problem in the metropolis,[143] and was in part accountable for the corruption which from this time forward disfigured its politics. By 1855 New York counted more than six hundred thousand inhabitants; a number which in itself must inevitably have created many a delicate situation in a new country, but which was rendered tenfold more difficult to manage by its rapid growth and heterogeneous character. It had doubled in fifteen years, and a continuously increasing stream of immigration had poured through it.