The invention of the modern traffic signal is credited to Garrett Morgan, an African American inventor and entrepreneur. In 1923, Morgan patented an early version of the traffic signal, which featured a "T-shaped" pole with three positions: stop, go, and an all-way stop position to allow crossing traffic to proceed.

Morgan's traffic signal was an important innovation that helped to improve road safety and reduce traffic accidents. His invention was eventually improved upon and became the basis for the modern traffic signal systems used worldwide today.

Garrett Morgan is also known for his other inventions, including the gas mask, which was used to protect soldiers during World War I and later used by firefighters and miners. He was a prolific inventor and entrepreneur who made significant contributions to the fields of safety and transportation.