Auguste Genevieve Valentin D'Avezac was born in May, 1780, near Aux Cayes in the French colony of Saint-Domingue, now Haiti. His father was a wealthy landowner, and he was educated in France at the College de Sorèze and the French Military College. In 1791, the slaves of Saint-Domingue revolted, which resulted in the deaths of Auguste's two older brothers, with the rest of his family fleeing to Virginia and New Orleans. In 1805, Davezac's sister Louise married Edward Livingston. Ten years later, their younger sister Aglae Pauline married Judge Henry Cox Carleton of New Orleans.