Forrest Mars, Sr., son of the founder of the Mars Company, Frank C. Mars, copied the idea for the candy in the 1930s during the Spanish Civil War when he saw soldiers eating chocolate pellets with a hard shell of tempered chocolate surrounding the inside, preventing the candies from melting.
Mars received a patent for his own process on March 3, 1941, and commenced production in a factory located in Clinton Hill, Newark, New Jersey. When the company was originally founded, it was M&M Limited. The two “Ms” represent the names of Forrest E. Mars Sr., the founder of Newark Company, and Bruce Murrie, son of Hershey Chocolate’s president William F. R. Murrie, who had a 20 percent share in the product. The arrangement allowed the candies to be made with Hershey chocolate, as Hershey had control of the rationed chocolate during the war years.
The demand for the candies during World War II caused an increase in production and its factory moved to bigger quarters in Newark, where it remained until 1958 moving to Charlottetown, New Jersey. During the war, the candies were exclusively sold to the military.
Shortly after wartime quotas ended and the candies were made available to the general public, Forrest Mars bought out Murrie’s shares in the company and took sole ownership of the M&M brand. The familiar brown bag package that remains in use today was introduced in 1948.
In 1950, a black “M” was imprinted on the candies giving them a unique trademark. It was changed to white in 1954. That year saw the introduction of peanut M&M’s which first appeared only in the color tan. They were debuted at the same time as the tagline “Melts in your mouth, not in your hand.” In 1960, M&M’s added the yellow, red, and green colors.
By 1956 M&M’s had become the No. 1 candy in the United States.
In 1964, Forrest E. Mars Sr. merged his various businesses with his father’s company, Mars Inc., and began to phase out external chocolate suppliers like Hershey’s.
By the 1980s, M&M’s were introduced internationally to Australia, Canada, Europe, Hong Kong, Japan, Malaysia, and the United Kingdom. M&M’s were the first candy to rocket into space in 1981 and three years later, they were advertised as the Official Snack of the 1984 Olympics in Los Angeles.