M&M's - Wikipedia
In 1950, a black "M" was imprinted on the candies giving them a unique trademark. It was changed to white in 1954. In the early 1950s, the Midwest Research Institute (now MRIGlobal) in Kansas City, Missouri, worked on behalf of M&M's to perfect a process whereby 3,300 pounds (1,500 kg) of chocolate centers could be coated every hour.
