Lonnie Johnson—a nuclear engineer—invented it by accident.
In the 19th century, train collisions happened at alarming rates. The problem was that rail workers couldn't properly communicate with each other. That is, until Granville T. Woods, better known as Black Edison, changed everything.
Martin Luther King, Jr. was assassinated on April 4, 1968. That same night, Robert F. Kennedy delivered the devastating news of King’s death to a group of African American supporters at a campaign rally. This is audio and video from that event.
In March of 1968, Martin Luther King Jr. traveled to Memphis, Tennessee to lead a group of striking sanitation workers in peaceful protest amid threats against his life. The threats were real. Martin Luther King Jr. was assassinated in Memphis on April 4, 1968.