Two men named William Kissam Vanderbilt were prominent members of the Vanderbilt family, descendants of Cornelius Vanderbilt. William K. Vanderbilt was the son of William Henry Vanderbilt and a grandson of "Commodore" Vanderbilt. He took an interest in managing the family`s railroad until middle age, and spent his later years pursuing horse breeding and living in his lavish mansions.
His son, William K. Vanderbilt II, was active in his early years in the family railroad business and became president of the New York Central Railway. His great passions, however, were horse racing and especially high-speed autos. He funded the establishment of the Vanderbilt Cup, a race that was run on Long Island. In order to facilitate auto traffic on Long Island, he formed a corporation that constructed the Long Island Motor Parkway. It operated as a privately-owned toll road but never generatd enough money to sustain itself, reverting to the state in lieu of back taxes in 1938. His son William K. Vanderbilt III was killed in an auto accident in 1933.