houn of South Carolina held that any state, if it considered a law of Congress unconstitutional, might suspend or nullify it. South Carolina declared the tariff of 1832 null, but Jackson compelled it to repeal the ordinance of nullification. He also deprived the United States Bank of the public funds. During 1829-37 all the machinery of American political parties came into being. In 1826 the railroads had begun and they made the growth of the west far more speedy. Our population in 1830 was 12,866,020. Anthracite was now at last used with commercial success. Steam navigation across the Atlantic was established (1838), the telegraph came in 1844, and the modern era of the United States opened. In 1835 the public debt was extinguished, and the surplus distributed among the states. In 1837 came a serious financial panic. (See Black Hawk; Calhoun, John C.; Clay, Henry; Crockett, Davy; Hayne, R. Y.; Houston, Sam.; Jackson, Andrew; Journalism; Kent, James; Newspapers; South Carolina; States' Rights; Texas; Story, Jos.; and Webster, Daniel.)
Van Buren succeeded Jackson in 1837, and replaced the national bank by the government treasury, but the hard times enabled the Whigs to elect William Henry Harrison. As he died soon after his inauguration (1841), Vice-President Tyler became president, and the Democrats rather than the Whigs ruled. They then elected Polk (1845-9) and Texas was annexed in 1845. War with Mexico followed (1846-8), America took possession of California and New Mexico, and Taylor and Scott won every battle with the Mexicans. Peace was concluded in 1848, Mexico ceding what now are Arizona, California, New Mexico, Nevada and Utah. The United States paid Mexico $15,000,000 and assumed $3,000,000 of Mexican debts to American citizens. At the same time (1844-6) the United States obtained the Oregon country (between the Rockies, Canada, the Pacific and California, Nevada and Utah) from England. Texan annexation had added 375,000 square miles to the country, the Mexican cession 500,000 and the Oregon country about 250,000. The United States, when the Gadsden purchase (1853) rectified the frontier between Mexico and New Mexico, had taken the dimensions it retained till 1867. (See California; Compromise of 1850; Fugitive Slave Law; Gadsden Purchase; Mexican War; Mexico; Mormons; Omnibus Bill; and Utah.)
But the discovery of gold in California (1848) and the non-existence of slavery in the Mexican lands brought political troubles. The Missouri compromise (1820) had prohibited slavery (except in Missouri) in the Louisiana country north of 36° 30′. Agitators at the north at once opened public opposition to slavery, and in 1831 a movement for the abolition of it began. (See Emancipation, Garrison and Phillips.) In 1820 the south and the north had already drifted apart in their views as to slavery, state sovereignty and the Union. New economic conditions controlled the north and the west, which the south hardly felt, and these widened the gulf between the sections. California applied for admission as a state, and forbade slavery. If it and other states from the new territory were to be free states, the slave-states would lose power and slavery would be endangered. In 1850 California was admitted as a free state, but a fugitive-slave law was passed.
Since 1830 material development had been extraordinary. The sudden increase of wealth gave fresh impetus to the spirit of invention. Goodyear's method of vulcanizing rubber (1839) came into universal use, McCormick invented the reaper (1834), which has been hardly less important to the country than the railroad, enabling it to fill the west rapidly and making western farms profitable. In 1846 came the power-loom, a successful sewing-machine and the surgical use of anesthetics. Next year brought the rotary press for printing. In 1847, too, European immigration first became an important factor in the making of the country. Its population in 1840 was 17,069,453. In 1850 it had become 23,191,876.
The Whigs elected Taylor (1849), who, however, died in July of 1850 and was succeeded by Fillmore. The Democratic party, had put forward the doctrine of squatter sovereignty or the proposal that the people of each territory be left to settle the question of slavery for themselves. The Whigs had ignored or evaded the problem. In 1854 Kansas and Nebraska were organized as territories, both being in territory where the Missouri compromise had prohibited slavery. The compromise was now repealed and the question of slavery was left to the people of these territories. The south and the north vied to see whether these people should be southerners and favor slavery, or northerners and favor freedom. Civil war in Kansas ensued, but the antislavery settlers were in a large majority and Kansas finally (1861) became a free state. Meanwhile a new party, an antislavery party only so far as it aimed to exclude slavery from the national territory, had arisen and had captured the popular branch of Congress. The Democratic party, which since 1852 had practically been the sole party, was faced by the Republican party. (See Chase, Salmon P.; Davis, Jefferson, Douglas, S. A., Kansas; Lincoln, Abraham, Seward, Wm. H.; Stanton, E. M.; Sumner, Chas.; and Underground Railroad.)
The Democrats had elected Franklin