You probably think you know the story. Garrett Morgan, a brilliant Black inventor, saw a car crash and decided the world needed a yellow light. It’s a clean, inspiring narrative often repeated every February. But honestly? The real story is way more interesting than the simplified version in school textbooks.
Morgan didn't just "invent the traffic light." People had been messing around with traffic signals since the horse-and-buggy days in London. What he actually did was solve a specific, deadly problem that was killing people on the streets of Cleveland.
👉 See also: How Do I SS on Macbook Without Losing My Mind
He was the first Black man in Cleveland to own a car. Think about that for a second. In the early 1900s, driving wasn't a relaxing commute; it was a chaotic nightmare. You had Model Ts, horse-drawn wagons, and pedestrians all fighting for the same dirt and cobblestone. There were no lanes. No turn signals. Just vibes and a lot of luck.
The Problem With "Stop" and "Go"
Before 1923, if a city had traffic signals at all, they were usually just two-position signs. Stop or Go. That was it.
Imagine driving your heavy, manual-crank car toward an intersection. The sign says "Go." Then, without a second of warning, it flips to "Stop." You can’t just slam on the brakes in a 1920s vehicle; you’d slide right into the middle of the street. Or worse, the guy behind you would plow into your trunk.
Garrett Morgan witnessed a particularly nasty wreck between an automobile and a horse-drawn carriage. The carriage driver was thrown, the horse was injured, and the car was a wreck.
It hit him: we need a "wait" state.
His solution wasn't a glowing yellow bulb—not yet. It was a T-shaped pole with mechanical arms. This device, which he patented as U.S. Patent No. 1,475,024 on November 20, 1923, had three positions.
🔗 Read more: MacBook Pro Chin Bar: Why That Logo Space Actually Matters
- Go: Allowing traffic to flow in one direction.
- Stop: Halting traffic.
- All-Stop: This was the genius part. It stopped traffic in every single direction simultaneously.
That "All-Stop" gave the intersection a few seconds to breathe. It allowed pedestrians to cross safely and let the cars that were already mid-intersection get out of the way before the cross-traffic started moving. Basically, he invented the "caution" interval.
Why the "Yellow Light" Label is Kinda Wrong
People love to say he invented the yellow light. Technically, he invented the function of the yellow light.
His actual machine used a hand-crank. An operator would stand there and turn a handle to rotate the arms. It was a semaphore system. If it was nighttime and traffic was light, he designed it so the arms could stay at "half-mast." This told drivers to proceed with caution—exactly like the blinking yellow lights we use today at 3:00 AM.
The three-color electric lights (red, yellow, green) were actually being developed around the same time by a police officer named William Potts in Detroit. But Potts never patented his.
Morgan did.
💡 You might also like: Mastering the Ray Diagram Convex Lens: Why Your High School Physics Teacher Was Right
He was a savvy businessman. He knew that an invention without a patent was just a gift to corporations. Eventually, he sold the rights to his design to General Electric (GE) for $40,000.
In 1923, $40,000 was a fortune. It’s over $700,000 in today’s money.
More Than Just a Traffic Guy
If you only know him for the traffic signal, you're missing out on his "safety hood."
Morgan was obsessed with saving lives. Before the traffic signal, he created a breathing device—a precursor to the gas mask. To sell it, he had to get creative. Because of the rampant racism of the era, many fire departments wouldn't buy from a Black inventor.
So, he hired a white actor to play "the inventor" while he disguised himself as a Native American assistant named "Big Chief Mason." He would go into smoke-filled tents to prove the mask worked.
It wasn't just a marketing gimmick. In 1916, there was a massive explosion in a tunnel 250 feet below Lake Erie. The air was toxic. Men were dying. Morgan and his brother Frank put on the masks, went down into the darkness, and pulled out the survivors.
He was a hero. But even then, some newspapers tried to downplay his role because of his race.
The Legacy of the Garrett Morgan Traffic Signal
So, why does this matter now?
We’re moving toward self-driving cars and AI-controlled "smart" intersections. But the logic is still Morgan’s. The idea that an intersection needs a transition period to clear out is a fundamental law of traffic engineering.
He didn't just build a T-shaped pole. He built a system of "caution."
Next time you’re sitting at a light waiting for that yellow to turn red, you're experiencing a legacy that started with a man watching a horse carriage crash in Cleveland.
Actionable Takeaways from Morgan’s Career:
- Solve the "Gap": Morgan didn't reinvent the wheel; he found the dangerous gap between "Stop" and "Go." Look for the "in-between" problems in your own field.
- Patent Your Ideas: Don't just be an innovator; be a protector of your intellectual property. GE bought the rights because Morgan had the legal paperwork.
- Adapt to the Market: If the front door is closed (like it was for Morgan due to segregation), find a side door. He used aliases and actors to ensure his life-saving tech reached the people who needed it.
- Safety First: Whether it was the gas mask or the signal, his best work came from a genuine desire to stop people from dying.
If you want to see the original prototype, it’s actually at the Smithsonian’s National Museum of American History. It’s a tall, awkward-looking thing that looks nothing like the LEDs we have now, but it’s the reason you got home safely today.