Jean-Baptiste Chavannes, born in 1748 in Saint Domingue, present-day Haiti, was the son of wealthy mulatto parents and received a good education. In 1779 he volunteered for an expedition with the Chasseurs-Volontaires de Saint-Domingue, a corps of Gens de Couleur from the island that consisted of Black and Mulatto soldiers. The Chasseurs were part of the fighting force under Charles Henri, Compte d'Estaing, Admiral of the French fleet that sailed to the American colonies to assist the Continental Army.
Chavannes distinguished himself during operations in Virginia and New York, especially during the retreat from Savannah in December 1778 after the failed expedition to oust the British from the city. Once the independence of the American colonies had been accomplished, Chavannes returned to Saint-Domingue.
He joined Vincent Ogé in 1790 who intended to petition the Colonial government in St. Domingue for voting rights for Gens de Couleur who owned property. Chavannes however wanted all the slaves to be declared free, but Ogé did not follow his advice and informed the assembly of his intention to take the opposite course. The mulattoes raised a force of about 1,000 men to rebel against the colonial government when their demands were rejected.