While the United States was embarking on Manifest Destiny and colonizing the West, southerners were pursuing Cuba and Central America as new states to bring into the Union as slave states. In 1848 President Polk announced that he was in favor of offering $100 million to buy Cuba but the offer was never sent. A Cuban solder of fortune named Narciso Lopez tried on several occasions to invade Cuba for the south and got help from southerners despite being thwarted on one occasion by the US government. He was able to land at one time but the attempt to create revolt in Cuba failed. Another soldier invaded Nicaragua on at least two occasions but was never able to keep his initial holdings.
(Book – Battle Cry of Freedom – James M. McPherson)