Complex sentence: Obadiah's wife died sometime prior to 1822 and in 1829 they sold the mills to Henry N. Hill and by 1831, the Griffins divested themselves of their properties and moved west to Niles, Michigan.
Split into simpler sentences: Obadiah's wife died sometime prior to 1822, and in 1829 the mills were sold to Henry N. Hill. By 1831, the Griffins divested themselves of their properties and moved west to Niles, Michigan.