Complex sentence: He was owned by members of the Duvernay family until 1846, when his petition for manumission, which was supported by his master, was granted by an all-white police jury in the city of New Orleans.
Split into simpler sentences: He was owned by members of the Duvernay family until 1846. His petition for manumission, which was supported by his master, was granted by an all-white police jury in the city of New Orleans.