I've got a lot of Kerrymen in the family tree, myself, but though Irish slave owners in the US might be rather uncommon demographically ( especially during the peak immigration years of 1845-1855, when Irish immigrants were mostly poor and slaves very expensive) , there's a very good example of an earlier one in Oliver Pollock. Born in Co. Tyrone, immigrated to Philadelphia in 1760, with his family, and quickly established himself as a merchant in the Caribbean trade. He got along well with the Spanish, notably including his fellow Irishman Alejandro O'Reilly, who had become an important official in Cuba. Pollock relocated to New Orleans in 1768, and managed to establish himself there, trading between the French, Spanish and British ports of the region. The majority of slaves going to the North American colonies went through the Caribbean first, and Pollock became a noted dealer in them, as well as a broker ( if someone had slaves they were not actually working themselves, Pollock would manage their hiring out to someone else) .

Pollock was a supporter of the colonists in the American Revolution, and when Spain became an ally to them Pollock became a supplier. One of the beneficiaries of his assistance was George Rogers Clark, who was trying ( rather unsuccessfully) to wage a war in the West against England. Like some other financiers of the Revolution, Pollock discovered that although the colonies and the Continental Congress were happy to get supplies, there were not at all willing and eager to pay for them, once the peace treaty was signed, and Pollock was pretty much left destitute. Although he was able to somewhat recover from that, he never seems to have become much more than poor, eventually living in Mississippi in his daughter's home. His papers, at the Library of Congress, are a very useful source for early American history and the early slave trade.