William Henry "Billy" Vanderbilt was an American businessman and philanthropist. He was the eldest son of Commodore Cornelius Vanderbilt, an heir to his fortune and a prominent member of the Vanderbilt family. Vanderbilt became the richest American after he took over his father's fortune in 1877 until his own death in 1885, passing on a substantial part of the fortune to his wife and children, particularly to his sons Cornelius II and William. He inherited nearly $100 million from his father. The fortune had doubled when he died less than nine years later.