M&M's chocolate candies were first introduced in 1941.
The product was developed by Forrest Mars Sr. in partnership with Bruce Murrie, whose father was president of the Hershey Chocolate Company. The two surnames supplied the initials in M&M's. Their hard sugar shell protected the chocolate from melting easily, making the candies especially practical for warm climates and military use.
Mars received a patent for the manufacturing process on March 3, 1941, and production began that year in Newark, New Jersey. The original candies contained semi-sweet chocolate and were later described as the plain or milk-chocolate variety. Their famous slogan, “melts in your mouth, not in your hand,” highlights the purpose of the candy coating.
The first major variety was Peanut M&M's, introduced in 1954. That date is a frequent source of confusion: 1954 marks the peanut version, not the launch of M&M's themselves. The candies are now sold in more than 100 countries and come in numerous colors and fillings.