When was the first American clock invented?
The first American clock was invented by a black man named Benjamin Banneker in 1761. He was only thirty years old at that time.
Actually the clock was invented by a bunch of people. The ancients created the sundial which was the first instrument to measure time. The guy you're thinking of is Eli Terry, who in 1797 received his first patent for a clock. He is known as the founder of the American clock-making industry. You can find more info on Wikipedia.