Garrett Morgan only received a sixth-grade education, but he was observational and a quick learner. While working as a handyman at the turn of the 20th century, he taught himself how sewing machines worked so that he could open up his own shop, selling new machines and repairing broken ones. While trying to find a fluid that would polish needles, Morgan happened upon a formula that would straighten human hair -- his first invention.
Morgan went on to save countless lives with his next two inventions. Troubled by how many firefighters were killed by smoke on the job, Morgan developed what he called the safety hood. The hood, which went over the head, featured tubes connected to wet sponges that filtered out smoke and provided fresh oxygen. This primitive gas mask became a sensation in 1916 when Morgan ran to the scene of a tunnel explosion and used his invention to save the lives of trapped workers. In 1923, as automobiles were becoming more common, Morgan went on to develop an early prototype of the traffic signal after seeing too many collisions.