Consists of business correspondence and documents concerning the Estillac plantation (also known as "Le Bonnet au Grand Boucan") in the French colony of Saint-Domingue, which is now the Republic of Haiti. Materials largely pertain to the operations and troubled finances of the plantation from the late 1750s through the early 1780s under the management of Guillaume Claude Besson, and later, Jean Guillaume Robillard. Many of the letters are addressed from various creditors and persons responsible for maintaining the Estillac plantation to Monsieur A. Mabille, a Paris-based hatter, trustee, and creditor. In total, there are over sixty letters, as well as several financial and genealogical documents related to the property and the families who managed it.

The correspondence primarily deals with various agricultural issues, particularly land acquisition and sugar production, the slave trade, financial difficulties, and problems with creditors. After Guillaume d'Aubarède, Marquis d'Aubarède (1717-1795) acquired a stake in the property from the Estillac family, Guillaume Claude Besson managed the plantation's operations. The collection includes letters to Mabille from the Marquis d'Aubarède, as well as a number of letters from Besson, who reports on the many difficulties he encountered, including partial abandonment of fields, dealing with creditors and settlers, the strenuousness of the labor, and diseases decimating enslaved laborers on the plantation. Besson's letters also present proposals for addressing the problems facing the plantation, such as his plan to abandon sugarcane production in favor of coffee and cocoa.

The Estillac plantation later passed into the hands of the Robillard family, whose letters describe the precise state of the property, sugar mills, and enslaved laborers as the family found them when they took over the management of the plantation. In particular, these letters relate the terrible physical condition of 155 enslaved laborers who were suffering from a tropical skin disease called "yaws," as well as the Robillards' plans to seek monetary damages and reimbursement for their care. The collection also contains letters from Lory, Plombard, and Compagnie, French traders based in Cap‑Français (Cap-Haïtien), who warn against investment in the plantation crops of Saint-Domingue, and advise speculation, instead, in the slave trade.

Additionally, there are letters from or mentioning individuals belonging to the families of Rohault, Bertrand de Laroque, De Ste. Marie, Gauthier, La Baron, Angot, Estillac, Mauny, De Survarenne, De la Borderie, and Guerin, as well as a genealogical table of the Robillard family. Some letters also mention war news and other current events, including the arrival of the squadron of Charles Henri, comte d'Estaing (1729-1794) in 1764.