Morgan, an African American entrepreneur and inventor, created the 3-Position Traffic Signal in the early 1920's.
Here are some more facts about Garret Morgan
Witnessing a traffic accident inspired him to create the 3-Position Signal. He figured there should be a third signal on a traffic post to caution drivers, pedestrians, and horse & buggies they will soon need to stop. Present day we call this a yellow light. His 3-Position Signal was the first to do this, and it was the the precursor to the 3-Light Signal we use today.
He only had a 6th grade education. He was forced to get a job and ended up working for sewing-machine factories. He used this time learn the machines inside and out. He was able to earn enough money to pay for a tutor to continue learning.
He patented an improved sewing machine, and started a repair business. While repairing a machine, he discovered a solution to straighten fabric hairs to make sewing easier. He applied this idea to African American hair, and created a creme. Shortly after, G.A Morgan Hair Refining Company established.
He invented the gas mask. There were skeptics who did not believe in this invention; until the Cleveland Waterworks Disaster of 1916....
After a tunnel explosion; workers became trapped and surrounded by toxic gases. Rescuers did not have the correct breathing equipment to save the workers. They continually failed. Garret and his brother strapped on his gas mask and entered the tunnel saving several trapped workers and rescuers.