In 1853 (he was not yet eighteen) Sam Clemens grew tired of his limitations and pined for the wider horizon of the world. He gave out to his family that he was going to St. Louis, but he kept on to New York, where a World's Fair was then going on. In New York he found employment at his trade, and during the hot months of 1853 worked in a printing-office in Cliff Street. By and by he went to Philadelphia, where he worked a brief time; made a trip to Washington, and presently set out for the West again, after an absence of more than a year. Onion, meanwhile, had established himself at Muscatine, Iowa, but soon after removed to Keokuk, where the brothers were once more together, till following their trade. Young Sam Clemens remained in Keokuk until the winter of 1856-57, when he caught a touch of the South-American fever then prevalent; and decided to go to Brazil. He left Keokuk for Cincinnati, worked that winter in a printing-office there, and in April took the little steamer, Paul Jones, for New Orleans, where he expected to find a South-American vessel. In Life on the Mississippi we have his story of how he met Horace Bixby and decided to become a pilot instead of a South American adventurer--jauntily setting himself the stupendous task of learning the twelve hundred miles of the Mississippi River between St. Louis and New Orleans--of knowing it as exactly and as unfailingly, even in the dark, as one knows the way to his own features. It seems incredible to those who knew Mark Twain in his later years--dreamy, unpractical, and indifferent to details--that he could have acquired so vast a store of minute facts as were required by that task. Yet within eighteen months he had become not only a pilot, but one of the best and most careful pilots on the river, intrusted with some of the largest and most valuable steamers. He continued in that profession for two and a half years longer, and during that time met with no disaster that cost his owners a single dollar for damage. Then the war broke out. South Carolina seceded in December, 1860 and other States followed. Clemens was in New Orleans in January, 1861, when Louisiana seceded, and his boat was put into the Confederate service and sent up the Red River. His occupation gone, he took steamer for the North--the last one before the blockade closed. A blank cartridge was fired at them from Jefferson Barracks when they reached St. Louis, but they did not understand the signal, and kept on. Presently a shell carried away part of the pilot-house and considerably disturbed its inmates. They realized, then, that war had really begun.