The expedition was absent for two years, and its report on returning added much to our geographical knowledge of the section. They were the first party of white men to cross the continent north of Mexico. Captain Lewis was appointed governor of Missouri Territory in 1806, and was acting as such when he committed suicide in 1809. Captain Clark was also governor of Missouri Territory, and afterward superintendent of Indian affairs. He died in St. Louis in 1838. THE BURR AND HAMILTON DUEL. No one read the wicked character of Aaron Burr more unerringly than Alexander Hamilton. He saw that he was ready to ruin his country for the sake of gratifying an insatiate ambition. Hamilton was always outspoken in expressing his opinions; and the hostility between the two became so bitter that Burr challenged Hamilton to a duel. Although the latter had had a son killed through the barbarous code within the preceding year, he was foolish enough to accept the challenge, and the duel was fought at Weehawken, New Jersey, July 12, 1804. Hamilton fired in the air, but Burr aimed straight for his antagonist and inflicted a wound from which he died the next day. Although Burr presided in the Senate after the duel, the whole country was shocked by the occurrence, and his friends fell away from him. In 1804, when Jefferson was re-elected to the presidency, George Clinton took the place of Burr as Vice-President. Burr then engaged in a plot to form a new empire in the southwest, the precise nature of which is uncertain. He found a few to join with him, but it came to naught, and in 1807 he was tried at Richmond, Virginia, on the charge of treason, but acquitted. He spent some years in wandering over Europe, and then returned to resume the practice of law in New York. He died in obscurity and poverty on Staten Island in 1836. [Illustration: DEVELOPMENT OF STEAM NAVIGATION FOLLOWING FULTON'S DISCOVERY.] A notable event of Jefferson's administrations was the first voyage of a steamboat up the Hudson. This was the _Clermont_, the invention of Robert Fulton, who was born in Lancaster County, Pennsylvania, in 1765. This boat was slightly over one hundred feet in length and about twenty feet broad, with side paddle-wheels and a sheet-iron boiler brought from England. There was general ridicule of the idea of moving boats by steam against a current, and the craft was called "Fulton's Folly." The crowd which gathered on the wharf in New York, August 1, 1807, indulged in jests which were not hushed until the craft moved slowly but smoothly up stream. Heading against the current, she made the voyage to Albany in thirty-two hours. She met with some mishaps, but after a time made regular trips between that city and New York, at the rate of five miles an hour. OCEAN STEAMERS.