 A native of St. Landry Parish in South Louisiana, he maintained his legal office for many years in Opelousas.In his last year in office, Dupré, by then an elderly deaf man, spoke out against the Long intra-party challenger, Dudley LeBlanc of Abbeville through the Long newspaper, the "Louisiana Progress".Dupré was born into an established French-American family, the son of Lucius Jacques Dupré (1822–1869) and the former Caroline Victoire Vanhille (1826–1896).