Complex sentence: Walter S. McIlhenny in turn succeeded his uncle Edward Avery McIlhenny, serving as president of McIlhenny Company from 1949 until his death in 1985.
Split into simpler sentences: Walter S. McIlhenny in turn succeeded his uncle Edward Avery McIlhenny. Walter served as president of McIlhenny Company from 1949 until his death in 1985.