Those two colorful letters are so familiar that “M&M’s” almost seem like a word of their own, but the name has a specific story behind it. The initials come from the surnames of the two men involved in creating and launching the candy: Forrest Mars Sr. of the Mars company and William F. R. Murrie, whose father was president of Hershey at the time. Their partnership brought together Mars’ business ambitions and Murrie’s connections to the chocolate industry.

The idea began in the late 1930s, when Forrest Mars was looking for a way to make chocolate easier to carry in warm temperatures. According to the company’s history, he was inspired by soldiers eating chocolate pellets covered with a hard sugar shell during the Spanish Civil War. The coating helped protect the chocolate from melting, eventually leading to the official U.S. launch of M&M’s in 1941.

The hard sugar shell was more than just a colorful design. It created a protective layer around the chocolate, making the candy easier to transport and store without melting as quickly. This feature proved especially useful during World War II, when M&M’s became associated with military rations because they could withstand travel better than uncoated chocolate.

Today, the small “m” printed on each piece is one of the candy’s most recognizable features. The chocolates originally came in a more limited range of colors, but the selection expanded over the decades. Combined with the distinctive lettering and colorful shells, those details helped make M&M’s one of the most recognizable chocolate candies around.