The rest of Sutter's history is soon told. In 1848, when Mexico ceded California to the United States, he was the owner of a vast domain, over which thousands of head of cattle wandered. A few years later, he was practically a ruined man--ruined by gold. On the eighteenth day of January, 1848, one of his men named Marshall, brought to Sutter a lump of yellow metal which he had uncovered while digging a mill-race. There could be no doubt of it--it was gold! News of the great discovery soon got about; there was a great rush for this new Eldorado; Sutter's land was overrun with gold-seekers, who cared nothing for his rights, and when he attempted to defend his titles in the courts, they were declared invalid, and his land was taken from him. To crown his disasters, his homestead was destroyed by fire; finding himself ruined, without land and without money, he gave up the struggle in despair and returned east, passing his last years in poverty in a little town in Pennsylvania. Fremont, meantime, had done a great work for California. The son of a Frenchman, showing an early aptitude for mathematics, he had secured an appointment to the United States engineering corps, and, after various minor expeditions in which he had acquitted himself well, was put in charge of an expedition for the exploration of the Rocky Mountains. He was fortunate at the start in securing the services as guide and interpreter of that famous hunter and plainsman, Kit Carson, whose life had been passed on the prairies, who knew more Indians and Indian dialects than any other white man, and who was, to his generation, what Davy Crockett was to an earlier one. To Carson a great share of the expedition's success was no doubt due, and it was so successful that in the following year, Fremont was leading another over the country between the Rockies and the Pacific. This one was almost lost in the mountains, and came near perishing of cold and hunger, but, finally, in March, 1844, managed to struggle through to Sutter's Fort. Fremont found California in a state of unrest amounting almost to insurrection against Mexican rule, and as the number of white settlers increased, this feeling grew, until Mexico, becoming alarmed, sent an armed force to occupy the country. The show of force was the one thing needed to fire the magazine; the settlers sprang to arms as one man, and, under Fremont's leadership, defeated the Mexicans and drove them southward across the border. Soon afterwards, General Kearny marched in from the east, from his remarkable and bloodless conquest of New Mexico, with a force sufficient to render it certain that California would never again be taken by the Mexicans.