At midnight in July 1916, a man arrived at a deadly gas-filled tunnel beneath Lake Erie still wearing his pajamas, carrying a strange canvas hood. Two professional rescue teams had already suffocated, but Garrett Morgan would dive in with his own invention and emerge a hero, fundamentally altering public safety engineering.

Morgan was a genius who designed devices to protect a society that often forced him to hide his own identity just to sell them. Born to formerly enslaved parents with only a sixth-grade education, he taught himself mechanics and chemistry, building a hair-care empire, a smoke hood, and the traffic signal, all while navigating crushing systemic prejudice at every turn.

• How tinkering with sewing machines became his real engineering education
• The accidental experiment that turned a needle lubricant into a ...