What year was it when the first car sold in US?

There's no single year that marks the first car sale in the US, as the definition of "car" and the nature of early sales were quite different from today's standards. However, 1896 is often cited as a significant year because it saw the first commercial sale of gasoline-powered automobiles in significant numbers. The Duryea Motor Wagon Company, for example, had a few sales that year. But even before that, individual vehicles were built and sold in small quantities.