Complex sentence: McIlhenny's grandfather, Edmund McIlhenny, had invented the fiery condiment, and his father, John Avery McIlhenny, had presided over the company from 1890 to 1898.
Split into simpler sentences: McIlhenny's grandfather, Edmund McIlhenny, had invented the fiery condiment. His father, John Avery McIlhenny, had presided over the company from 1890 to 1898.