The correct answer to this open question is the following.
Sectionalism arose from the Denmark Vesey Plot and the abolitionist
movement because the Denmark Vesey plot made things worse with the racial and slavery issue in the South. The Denmark Vesey Plot contributed to the increase of sectionalism in that the General Assembly responded with measures making it harder to free slaves, angering abolitionists.
Denmark Vesey had been plotting a black people insurrection in July 1822, using his position at the local Methodist church. It is said that he had been organizing 1000 black people to take the city of Charlestown, in South Carolina, when one slave showed his loyalty to his owner and revealed the plot. White authorities acted promptly and they prevented the riot, arrested Vesey and other leaders, and the sentence was they were executed.
