Despite a small but influential class of Americans who copied foreign manners, the United States of America had gained something of a national character in European estimation. In the New World alone, labor was deemed compatible with gentility. The increasing facilities of traffic and manufacture gave a tremendous impulse to the development of the country. Thus a surprising number of railroads were opened in the States of New York, Pennsylvania and Ohio. Improvements connecting Philadelphia and Pittsburg were completed at a cost of twelve million dollars. Several thousand miles were covered by canals. [Sidenote: Development of the United States] [Sidenote: Chicago founded] [Sidenote: Black Hawk war] The American census of 1831 showed nearly 13,000,000 inhabitants, a doubling of the population since the beginning of the century. An area of 725,406 square miles of territory was contained in thirty-four States and three Territories. The population spread westward, no longer in large groups, but in small bodies of pioneers, travelling along the chief rivers. West of the Missouri River all was still virgin soil. During this year Schoolcraft discovered the source of the Mississippi. The settlement of Chicago was laid out and the first sale of lots there was held. A boundary and commercial treaty was concluded with Mexico in the spring. Later in the year President Jackson obtained from the French Government a promise of 25,000,000 francs indemnity for the spoliations on American commerce made under Napoleon. On April 21, the so-called Black Hawk war broke out with the Indian tribes of the Sacs and Foxes. Some 6,500 soldiers were despatched to subdue them. In this war it so happened that Abraham Lincoln and Jefferson Davis served as captain and lieutenant. [Sidenote: Abolitionist movement] [Sidenote: William Garrison] [Sidenote: Nat Turner's revolt] The issue of slavery was brought to the front early in the year. On the first day of January, Garrison's "Liberator" appeared in Boston. Garrison advocated immediate and unconditional emancipation of the black slaves. In his first issue he said: "I will not retreat a single inch, and I will be heard." It was not long before Garrison made himself heard, and gathered about him a few men and women as determined as himself. Among them was the young poet Whittier, Louis Tappan, and Lucretia Mott, the Quaker. A storm of obloquy and persecution was raised against Garrison. Social and public ostracism was visited upon him and his fellow abolitionists. Garrison's efforts to free the negroes were made especially unwelcome in the South by an insurrection of blacks led by Nat Turner of South Hampton. The revolt was speedily suppressed, and Turner with seventeen of his followers suffered death by hanging. Turner's attempt called forth a debate of several weeks in the Virginia Legislature, remarkable throughout for its exposure of the evils of slavery and their bad effect on national prosperity.