The antagonists in Kansas acted.  The roving Missourians who kept crossing the line carried weapons to back up their arguments.  New England abolitionists shipped boxes of rifles, "Beecher's Bibles," to the antislavery settlers.  (An eminent antislavery clergyman, Henry Ward Beecher, had incautiously remarked that a rifle might be a more powerful moral agent on the Kansas plains than a Bible.)  Sporadic shootings and barn-burnings culminated, in May 1856, in a raid by Missouri "border ruffians" on the free-soil town of Lawrence.  They sacked the place, destroyed the type and press of an antislavery newspaper and terrorized the inhabitants.  A few days later john Brown, a grim abolitionist fanatic, retaliated.  He and his ons and companions undertook a foray through the valley of Potawattomie Creek, where they stole horses, murdered five settlers, and mutilated their bodies.  Brown claimed that he was an agent of the Lord, assigned to punish those who favored slavery.  His inexcusable atrocities, lamentable by any reasonable standard, spurred a counterattack by proslavery men, who fell upon Brown's band, killed one of his sons, and burned the settlement at Osawatomie.  Though federal troops prevented further private war, the slavery issue had brought blood and terror to Kansas.

The first governor of the territory, Andrew H. Reeder, a Pennsylvania Democrat, found that several thousand settlers had preceded him to Kansas.  In the fall of 1854 he called an election to choose a territorial delegate to Congress, and early in 1855 he called another election to name a territorial legislature.  But Kansas elections developed unusual features.  The Missouri counties which bordered Kansas on the east were strong proslavery areas, and the people in these counties, urged on by leaders like Senator Atchison, did not want a free-soil territory next door. Missourians by the hundreds swarmed across the border to Kansas to vote in the territorial elections.  The antislavery settlers, though apparently in the majority, were heavily out-voted.  On the face of the returns, the new territory had chosen a proslavery delegate to Congress and had elected a solidly proslavery legislature.  The legislature, in turn, at once adopted a stringent slave code, providing the death sentence for anyone who helped a fugitive slave to escape and a prison term for anyone who held that slavery was not legal in Kansas.

But the Democratic convention, where expansionist sentiment was stronger, denied Van Buren the nomination he coveted. Instead, the delegates chose James K. Polk of Tennessee, whose commitment to territorial expansion was clear and unqualified. To avoid the accusation of sectional favoritism, the Democratic platform cleverly united a demand for the admission of Texas with a demand for the acquisition “of the whole of the Territory of Oregon.” The platform also made the dubious assertion that the United States had a clear title to both. It followed, therefore, “that the re-occupation of Oregon and the re-annexation of Texas at the earliest practicable period are great American measures, which this convention recommends to the cordial support of the Democracy of the Union.” By combining the expansionist desires of South and West, the Democrats had found a winning formula. Throughout the campaign Manifest Destiny transcended all other issues, so much so that Clay began to shift his position on Texas. He would favor annexation after all if it could be accomplished without war and upon “just and fair terms.” But this commitment still sounded halfhearted when compared with the spread-eagle oratory and aggressive slogans of the Democrats.

In the Northern strongholds of anitslavey sentiment the new law simply could not be enforced; during the 1850s abolitionists executed a series of dramatic rescues of fugitives and sent them on to Canada and freedom.  Moreover, various Northern states passed personal liberty laws which nullified the fugitive slave act or at least interfered with its enforcement.  This was an assertation of state rights and a form of nullificaton that Southerners scarcely appreciated.