His son Zephaniah Kingsley Jr. returned to Charleston, South Carolina, in 1793, swore his allegiance to the United States, and began a career as a shipping merchant. His first ventures were in Saint-Domingue, during the Haitian Revolution, where coffee was his main interest as an export crop. He lived in Haiti for a brief period while the fledgling nation was working to create a society based on former slaves transitioning into free citizens. Kingsley traveled frequently, prompted by recurring political unrest among the Caribbean islands.