THE European nations had abolished the actual trade in slaves at dates between 1801 and 1815, but American ships continued the trade, with the horrors of the passage and of the native wars which it stimulated. In 1820 the famous Missouri compromise was made. Missouri was admitted as a slave state, but all the states existing or still to be formed north of the latitude 36 30 were to be free. This gave twelve slave and twelve free states. The future, however, rested with the free party, as the area open to them for expansion was much greater than that open to the slave states.
A fierce quarrel occurred in 1828-32 when the Federal government, controlled by the North, enacted a heavy tariff on imported goods, which South Carolina defied, in the end with success. A war with Mexico was fought in 1846-48, largely in Southern interests, and territory was gained for slavery. California, however, came in as a free state. A further compromise was made in 1850 providing for the return of runaway slaves, and in 1854 the Missouri compromise was set aside, Kansas and Nebraska, north of the line, being allowed to decide their condition by vote. There was a local civil war of murders and ambushes between the two parties, who included the usual large proportion of plain gunmen, passionately devoted to causes which they did not well understand. Whether or not John Brown was one of them, or something better, is uncertain-most probably the latter. After taking a bloody part in the Kansas disorder, he tried to raise a slave rebellion in Virginia, failed, and was hanged in 1859.
Meanwhile there was a growing demand in the North for action to end slavery. The Southerners might easily have ignored it, since it could not have obtained the necessary majority of States, House of Representatives, and Senate, required by the Constitution to carry such an amendment, but the last straw came when Abraham Lincoln, an Illinois politician who had been a leading advocate of abolition, was elected President in 1860. Lincoln's rise to prominence was in the teeth of great handicaps and formidable rivals, and the whole question of his motives is rather obscure. It seems fairly clear that at first he intended to prevent the extension of slavery, but not to abolish it where it existed. The South, however, took alarm and early in 1861 South Carolina seceded from the Union, and was joined by the other slave-owning states. Practically all the non-slave states supported Lincoln, though the support of the new West was not active.