In 1814, Zephaniah Kingsley moved to Fort George Island and what is known today as the Kingsley Plantation. He brought a wife and three children (a fourth would be born at Fort George). His wife, Anna Madgigine Jai, was from Senegal, West Africa, and was purchased by Kingsley as a slave. She actively participated in plantation management, acquiring her own land and slaves when freed by Kingsley in 1811.
With an enslaved work force of about 60, the Fort George plantation produced Sea Island cotton, citrus, sugar cane, and corn. Kingsley continued to acquire property in north Florida and eventually possessed more than 32,000 acres, including four major plantation complexes and more than 200 slaves.