By the early 1840s, Benjamin was wealthy from his law practice and, with a partner, bought a sugar cane plantation, Bellechasse. This purchase, and the subsequent construction of a grand house there, advanced Benjamin's ambitions; the planter class controlled Louisiana politics and would trust only a man who also owned substantial land and slaves. The Benjamin marriage was by then failing, and he hoped in vain that his wife would be content at the plantation. Benjamin threw his energy into improving Bellechasse, importing new varieties of sugar cane and adopting up-to-date methods and equipment to extract and process the sugar. He purchased 140 slaves to work the plantation, and had a reputation as a humane slaveowner.