The first great step came about 1835, when the abolitionists, in part encouraged by the English acts abolishing slavery in the West Indies (1830-35), began to send petitions to Congress asking for the prohibition of slavery in the District of Columbia. The South was able to influence enough Northern votes to secure a succession of gag resolutions, intended to prevent discussion in Congress; but the question sprang up in many unexpected ways. The apparently innocent power of carrying mails by the Federal government brought to light objections to the delivery of abolition mail at the Southern post offices. The Southern leaders attempted to stop the rising tide of dis cussion of slavery in Congress ; but John Quincy Adams arose as the champion of free speech, and he was speedily aided by other men like Joshua R. Giddings of Ohio, who would not be silenced.
By 1842 it was plain that nobody could pre vent the discussion of slavery throughout the North and in Washington; soon it had to be discussed, because of new questions of Terri torial slavery. The principle of dividing the Union by a geographical line continued by the Missouri Compromise of 1820 was tested again when in 1845 Texas was brought into the Union with the express purpose of furnishing material for a body of slave-holding States; Congress deliberately prohibited slavery in the territory claimed by Texas north of 36° 30'.
Then followed, in 1848, the annexation of New Mexico and California, with the plain ex pectation that the 36° 30' line would be pro duced to the Pacific. The North, however, was aroused and the people of California refused either to divide their Commonwealth or to ad mit slavery within its borders. By the com promise of 1850, California was acknowledged free, and New Mexico and Utah were prac tically left as fighting ground for slave power ; yet Congress, in 1848, passed a fourth significant act prohibiting Territorial slavery, this time in Oregon. In the same compromise of 1850, Congress passed a new Fugitive Slave Law and prohibited slavery in the District of Columbia.
The contest was raised again by the Kansas Nebraska Act of 1854. framed by Douglas, which repealed the Missouri Compromise and, by implication, the three other acts prohibiting slavery in the Territories; and left Kansas to be controlled by the first set of people who might get on the ground. Contrary to expectation, the first set were from the North, and the de termination of the Southern settlers in Missouri and of the South generally to take possession of Kansas in spite of the will of the majority of the settlers occasioned a civil war in Kansas, six years before the greater national Civil War.
By this time it became evident that slavery was a political question which divided the nation; and in 1856 the first large and wide spread party was formed. The Died Scott Decision of 1857 was an attempt to suppress the controversy, and to take it out of politics, by denying the right of Congress to prohibit slavery in a Territory, though that right had four times been exercised, with little op position. From this time the drift was steadily and irresistibly toward Civil War,— and the crisis was reached in 1860, when the Southern Democracy demanded, as a condition of remain ing in the Union, their right to share in all ter ritory thereafter annexed, and to have an end of abolition agitation in the North.
Although in a resolution of 22 July 1861 the House of Representatives declared that slavery was not the cause of the war nor the freeing of the slaves its purpose, from the beginning it was plain that slavery was the great question which divided the two sections, and that corise quently its future was inextricably woven into that struggle. Hence, the war had hardly be gun before there came a series of special enact ments and executive proclamations. (1) On 26 April 1862 an act of Congress freed the slaves in the District of Columbia, with a com ensation of about $300 a head. (2) On 19 June 1862 an act, in flat defiance of the Dred Scott Decision, prohibited slavery in every Ter ritory. (3) On 2 July 1862 an act was passed providing that slaves of persons engaged in re bellion against the United States thereby gained their freedom. President Lincoln was all the while turning over in his mind a larger scheme, and on 22 Sept. 1862 he issued a preliminary proclamation, followed on 1 Jan. 1863 by a final proclamation, of emancipation, by -which all slaves within the seceding States were declared free, excepting in the State of Tennessee, and certain districts of Virginia and Louisiana which were within the Federal lines.
To the national prohibitions of slavery in the Territories, the District of Columbia and the seceded slave States were added the actions of three slave-holding communities: West Vir ginia, by its Constitution (21 March 1862), Missouri by a vote in convention (1 July 1863), and Maryland by a new constitution (13 Oct. 1864), declared for absolute or gradual eman cipation. They thus joined the cohort of free dom, so that at the end of the war the only re gions within the boundaries of the United States in which slavery remained legal were Delaware, Kentucky and Tennessee, the last of which States declared for freedom by a new constitution in 1865.