Franklin Pierce, John Brown and the dismantling of the Compromise of 1850.
The big issue of his presidency was Kansas-Nebrasak Act and Bleeding Kansas. Find the story of what happened at Pottowatomie Creek and how this established a reputation for John Brown both in the North and in the South (and obviously that reputation was different in the two regions).
The Kansas-Nebraska Act had provided that the issue of Slavery would be decided by popular sovereignty. Both pro slave and anti-slavery elements in Kansas forcefully defended their position, at times forcefully so. Both sides brought people in sympathetic to their cause in an attempt to influence the election of the territorial legislature. Many who came were not in favor of slavery; but were racist and determined to keep blacks out of the territory.
A territorial legislature was elected in 1855 comprised primarily of pro-slavery members; however the free territory people called the election a fraud and elected their own legislature. Two governments thus sat in Kansas, each labelling the other as bogus.
Matters soon turned violent. Pro-slavery forces attacked the "free town" of Lawrence, destroyed homes and property, and killed one man. John Brown, a failed wool merchant from the East had moved to the area at the request of several of his sons who had settled there. Brown was a religious fanatic who believed that God had called upon him to "break the jaws of the wicked." He as incensed at the attack on Lawrence. As a result, Brown and his sons attacked the pro-slavery settlement of Pottawatomie Creek, dragged five men from their homes and hacked them to death with swords in front of their families. This provoked a counter attack by pro-slavery forces who killed one of Brown's sons.
Brown was forced to flee the territory and grew a beard to disguise himself. He still remained active in the anti-slavery campaign, often speaking at abolitionist rallies. He continued until he participated in the raid at Harper's Ferry where he was captured, tried for treason and hanged.
Franklin Pierce's role in all of this was to attempt to play peace maker. He attempted to reconcile the abolitionist and slavery elements, but lines were too firmly drawn, and he only succeeded in alienating both sides. Before he finished his first year in office, his own party abandoned him as a failure.