The word "invent" comes from a Latin word which means "to find." Garrett Morgan, an African-American, was one such inventor. His first job was repairing machines in a factory. By accident, he had invented the hair straightener. He sold his products and then continued with his career as an inventor.
Every day, Garrett Morgan watched traffic become more dangerous. Cars, bicycles and walkers all competed to cross the street. Police officers made simple "stop / go" signals at busy crossroads, but cars, bicycles and walkers still rushed into the crossroads at different speeds and many crashed into each other. One day he saw a traffic accident between a car and a bicycle at a busy crossroads. he realized ,the problem with the traffic light, was its poor design: the traffic signal lacked a transition (过渡) between "stop" and "go."
Morgan invented a new traffic signal that added a "caution (警告)" light that made traffic move more smoothly and safely. His traffic light stood on a T-shaped pole (杆) with arms that flashed a red light to stop traffic in all directions, allowing walkers to cross safely. After walkers crossed, traffic could only go in one direction.
Soon, cities everywhere wanted his traffic light. In 1923, a popular electric company paid Morgan $40,000 to make and sell his invention. Traffic lights today work in the same basic way.
The traffic light is Morgan's most famous invention. In 1963, the United States government gave Garrett Morgan an award for his life-saving idea.