What were the only two U.S. automobiles that featured a V16 engine?

It was an era when the place in the hierarchy of automobile pecking order was somewhat determined by the number of cylinders a car's engine had. The lowly Model T had only four. The Buick and other mid-sized vehicles had eight cylinders. Some Lincolns, Auburns, and Packards possessed twelve cylinders. So, at the height of the Great Depression both Marmon and Cadillac one-upped all other American-made cars with their v-16! Cadillac made a few over 4,000 of the extremely expensive cars between 1930 and 1940. Before that time Marmon had gone out of business.