Holmes got the idea after assisting a friend of his from business school, John Wiley, after Wiley's Model T flipped over into a ditch. Holmes then modified his 1913 Cadillac to pull cars and transport them to his garage by affixing an iron chain, a pulley, and several poles to the back of his Cadillac. Holmes quickly patented his invention, and thus the towing industry was born. He spent the next two years theorizing and forming a concrete idea, filing his patent on January 17, 1918.