19. On leaving his capital, Santa Anna turned about to attack the hospitals at Puebla. Here eighteen hundred sick men had been left in charge of Colonel Childs. A gallant resistance was made by the garrison, until General Lane, on his march to the capital, fell upon the besiegers and scattered them. It was the closing stroke of the war. [Sidenote: Treaty of Guadalupe Hidalgo.] 20. The military power of Mexico was completely broken. In the winter of 1847-48, American ambassadors met the Mexican Congress at Guadalupe Hidalgo, and on the 2d of February a treaty was concluded. By the terms of settlement the boundary-line between Mexico and the United States was established on the Rio Grande from its mouth to the southern limit of New Mexico; thence westward along the southern, and northward along the western boundary of that territory to the Gila; thence down that river to the Colorado; thence westward to the Pacific. New Mexico and Upper California were relinquished to the United States. Mexico guaranteed the free navigation of the Gulf of California and the river Colorado. The United States agreed to surrender all places in Mexico, to pay that country fifteen million dollars, and to assume all debts due from Mexico to American citizens. [Sidenote: California and Wisconsin Admitted.] 21. A few days after the signing of the treaty, a laborer, employed by Captain Sutter on the American fork of Sacramento River, in California, _discovered some pieces of gold in the sand_. The news went flying to the ends of the world. Men thousands of miles away were crazed with excitement. From all quarters adventurers came flocking. Before the end of 1850, San Francisco had grown to be a city of fifteen thousand inhabitants. In September of that year, California was admitted into the Union; and by the close of 1852, the State had a population of more than a quarter of a million. 22. In 1848 Wisconsin was admitted into the Union. The new commonwealth came with a population of two hundred and fifty thousand. Another presidential election was already at hand. General Lewis Cass, of Michigan, was nominated by the Democrats, and General Zachary Taylor by the Whigs. As the candidate of the new Free Soil party, ex-President Martin Van Buren was put forward. The memory of his recent victories in Mexico made General Taylor the favorite with the people, and he was elected by a large majority. As Vice-president, Millard Fillmore, of New York, was chosen. CHAPTER XLI. ADMINISTRATIONS OF TAYLOR AND FILLMORE, 1849-1853. The new President was a Virginian by birth, a soldier by profession. During the war of 1812 he distinguished himself in the Northwest. In the Seminole War he bore a part, but earned his greatest renown in Mexico. His administration began with a violent agitation on the question of slavery in the territories. [Sidenote: Slavery in the Territories.]