At eighteen Levy—having dropped the Yuli surname—left the region for the
Danish Virgin Islands, where he established himself as a leading merchant in
Charlotte Amalie, St Thomas. During his time in the Virgin Islands Levy engaged in the lumber business. His commercial career developed within the slave-based economy of the Caribbean, where lumber, provisions, credit, shipping, sugar, and other plantation commodities were tied to enslaved labor. Historians describe Levy as a merchant-shipper with extensive business dealings connected to the slave trade in England, Europe, and the Americas. In 1803 he married Hannah Abendanone (1786–1872), the daughter of a local merchant, David Abendanone, and his wife, Rachel. They had four children. The youngest,
David Levy Yulee (1810–1886), became the first Jew elected to the United States Senate, representing Florida. Moses Levy's firm of Levy & Benjamin pursued an extensive trade throughout the Caribbean, operating in ports and markets shaped by slavery and the movement of slave-produced goods. Philip Benjamin, his cousin and business partner, was the father of
Judah P. Benjamin, future Confederate Secretary of State. Levy eventually left this firm and ran his own business centered in San Juan, Puerto Rico and then Havana, Cuba, both major slave societies in the nineteenth-century Caribbean. His friendship with
Alejandro Ramirez, the superintendent of Cuba and the Floridas, was influential in expanding Levy's business horizons. At one time Levy supplied General
Pablo Morillo's massive expeditionary forces in Venezuela with food, munitions, and other supplies. Influenced by evangelical culture, in 1816 Levy underwent a spiritual epiphany, an event that was at least partially attributable to a rancorous and long-failing marriage. After a rare, formal divorce granted by the Danish king (1818) Levy abandoned a flourishing business in favor of a life devoted to what he called the "sacred cause" of reform. His plans included an "asylum" for Jews who were then suffering extensive abuse in post-Napoleonic Europe. Despite his wealth, Levy feared it would lead to sin. In 1820, he purchased 53,000 acres of land in what is now
Lake City, Florida, near the
St. John's River. He later bought more land in what is now
Alachua County and
Marion County, Florida, establishing agricultural enterprises including the sugar plantation Hope Hill and Pilgrimage Plantation. Levy was himself a slaveholder, and most of the labor at Pilgrimage was performed by enslaved people; one account states that of about thirty people employed there, only eight or nine were white. Estimates of enslaved people at Pilgrimage range from 15 to 31 at different times. Although Levy later advocated gradual emancipation and published
A Plan for the Abolition of Slavery in 1828, his Caribbean wealth, sugar ventures, and Florida plantations were rooted in slave labor. His work to reintroduce sugarcane to the region has been described as hastening the expansion of slavery in southern Florida. ==Reform advocate==