But the Compromise of 1850 had loosed from its Pandora’s box another fomenter of trouble, in the idea of leaving to the people of the Territories the settlement of whether their incoming States should be slave or free,—­the doctrine of “popular sovereignty” as it was called.  The nation had accepted that theory as a makeshift for the emergency of that day; but slave cultivation had already exhausted much of the Southern land, and, not content with Utah and New Mexico for their propagandism, the slaveholders cast envious eyes upon the great territory of the Northwest, stretching out from the Missouri border, although it was north of the prohibited line of 36 deg. 30’.  And so it came about that, within four short years after the compromise of 1850, the unrest of the North under the Fugitive-Slave Law, followed by the efforts of the South to break down the earlier compromise of 1821, awoke again with renewed fierceness the slavery agitation, in discussing the bill for the organization of the Territories of Kansas and Nebraska,—­an immense area, extending from the borders of Missouri, Iowa, and Minnesota, west to the Rocky Mountains, and from the line of 36 deg. 30’ north to British America.

The mover of the Kansas-Nebraska Bill, Stephen A. Douglas, Senator from Illinois, a Democrat and a man of remarkable abilities, now came into prominent notice.  He wanted to be President of the United States, and his popularity, his legal attainments, his congressional services, his attractive eloquence and skill in debate, marked him out as the rising man of his party, He was a Vermonter by birth, and like Lincoln had arisen from nothing,—­a self-made man, so talented that the people called him “the little giant,” but nevertheless inferior to the giants who had led the Senate for twenty years, while equal to them in ambition, and superior as a wire-pulling politician.  He was among those who at first supposed that the Missouri Compromise of 1821 was a final settlement, and was hostile to the further agitation of the slavery question.  He was a great believer in “American Destiny,” and the absorption of all North America in one grand confederation, in certain portions of which slavery should be tolerated.  As chairman of the Senate Committee on Territories he had great influence in opening new routes of travel, and favored the extension of white settlements, even in territory which had been given to the Indians.

To further his ambitious aspirations, Douglas began now to court the favor of Southern leaders, and introduced his famous Kansas-Nebraska Bill, which was virtually the repeal of the Missouri Compromise, inasmuch as it opened the vast territories to the north of 36 deg. 30’ to the introduction of slavery if their people should so elect.  This the South needed, to secure what they called the balance of power, but what was really the preponderance of the Slave States, or at least the curtailment of the political power of the Free States.  In 1854, during the administration of Franklin Pierce, and under the domination of the Democratic party, which played into the hands of the Southern leaders, the compromise which Clay had effected in 1821 was repealed under the influence of his compromise of 1850, and the slavery question was thus reopened for political discussion in every State of the Union,—­showing how dangerous it is to compromise principle in shaping a policy.