After Jackson would win an overwhelming victory in 1828, his presidency would be full of controversies that would threaten to divide the nation. In 1828, Jackson would push Congress to approve a tariff that would put them at their highest rate. Southern planters were greatly affect by this as they trade much of their cotton on the world market. They saw is as assisting northern interests and it would ultimately lead to South Carolina threatened disunion. His VP Calhoun secretly write to southern leaders asserted that their state had the right to declare the tariff void if their state legislature did not approve of it in 1828. Although Jackson understood how this would affect the South, he was more concern with keeping the union strong, and this called for the strengthening of a central government. Jackson was determined to not back down from Calhoun over this issue, and it would lead to a bitter rivalry between the two men. The final blow would appear to be when Jackson discovered that Calhoun had advised President Monroe to censure then-General Jackson after he invaded Spanish Florida in 1818 when Calhoun was the Secretary of War. Calhoun's and Jackson's relationship deteriorated further.