Researching Zephaniah Kingsley

Kingsley was a relatively lenient slaveholder, who allowed his slaves the opportunity to be hired out and purchase their freedom. He was in favor of "interracial" marriage, which produced, he explained in a pamphlet Treatise, healthy, beautiful children. He followed his own advice, and took four enslaved African women as concubines or common-law wives, practicing polygamy. He claimed to have married one of them, and the marital status of the others does not seem to have ever been an issue. Certainly they could not marry under Territorial Florida law, but since the women were enslaved, what Kingsley did with them was not unusual. He had nine mixed-race children with these wives, and no white children. He educated his children to high standards and worked to ensure he could settle his estate on them and his wives

His first wife, Anna Madgigine Jai Kingsley, was 13 years old when Kingsley purchased her in Havana; he remarked on the convenience of buying a wife. He said that he had married her, which he never said of his three other concubines or common-law wives. But it was not a legal, Catholic marriage, as that would have produced documentation; if it did take place, it was some African ceremony, performed in Cuba. He emancipated Anna Jai when she turned 18, and trusted her with running his plantation when he was away on business.

His interracial family and his business interests resulted in Kingsley being deeply invested in the Spanish system of slavery and society. As in the French colonies, certain rights were provided to a class of free people of color, and multiracial natural children were allowed to inherit property from white fathers. "In the Spanish Floridas free people of color... enjoyed tremendously elevated status when compared to virtually any other person of African descent in North America."

Kingsley became a member of the territorial legislature when, in 1821, Spanish Florida became Florida Territory. He argued in favor of continuing the status of "free negro", as in the Spanish or French colonies, tried to persuade the new territorial government to maintain the special status of the population of free people of color, who were mostly "multi-racial". He was unsuccessful in this effort, and in 1828 he published a pamphlet that defended a system of slavery that would allow slaves to purchase their freedom, and give rights to free blacks and free people of color. Faced with American laws that forbade interracial marriage, and discouraged "free people of color" (see Free Negro#Free Negroes unwelcome) being allowed to stay or settle in the state, between 1835 and 1837 Kingsley relocated his large family to Haiti. (Kingley's former plantation, Mayorasgo de Koka, is today in the Dominican Republic.) After his death, his estate in Florida was the subject of dispute between his widow Anna Jai and other members of Kingsley's family, but she was successful in gaining the estate he had bequeathed to her.

Kingsley casually changed nationalities. Born British, at different moments in his life he was a citizen of the United States, Spain (Spanish Florida), and Denmark (the latter because it facilitated his slave trading business).