The Monsanto family is a historical Sephardic Jewish merchant, banking and various business dealing with the government. who played a significant role in founding the Jewish community in Colonial Louisiana (then transferring between French and Spanish rule) in the 18th century. They had originated in the Iberian Peninsula but moved to Amsterdam and spread out through the Dutch Empire and to the Americas at Curaçao. The family arrived in Louisiana in the 1760s, and one of their members, Isaac Monsanto, was one of the wealthiest merchants in New Orleans. The family engaged in the Atlantic slave trade and owned African slaves at their plantations at Natchez, Mississippi (this was later known as Glenfield Plantation) and Trianon, New Orleans. Not including their former estate in New Orleans, by the 1780s, the Monsantos kept 51 slaves for their personal use and sold other enslaved African people to Louisiana plantations. The Monsanto family were Sephardic Jews, who derive their name from Monsanto (meaning "Holy Mountain"), a village in Portugal. They had lived for a time as Marranos; people who outwardly conformed to the Catholic Church but continued to practice Judaism in private. They were active in trade in Andalusia, Spain (they were located at Sevilla and Málaga) for a time during the 17th century, before moving on to Amsterdam, in the United Provinces of the Netherlands during the lifetime of Isaac Rodriguez Monsanto (1645—1695). It is in the Netherlands that the Monsanto brothers who came to the Americas were born. They first moved out across the Atlantic Sea to Curaçao in the Caribbean, which was then part of the Netherlands Antilles. In the aftermath of the Seven Years' War, with both realms under the House of Bourbon, the Treaty of Fontainebleau (1762) stipulated that French Louisiana, then part of New France, be transferred to New Spain as Spanish Louisiana. The transfer was actually gradual and in a state of flux during the time that the Monsanto family arrived.