Garrett A. Morgan (1877-1963 ) was granted a U.S. patent for a traffic signal on November 20, 1923. The Morgan traffic signal was a T-shaped pole unit that featured three positions: Stop, Go and an all-directional stop position. This "all stop" position stopped all traffic to allow pedestrians to cross streets.
Morgan's traffic signal was used throughout North America until it was replaced by the red, yellow and green-light traffic signals you see used today. Morgan sold the rights to his traffic signal to the General Electric Corporation for $40,000.