It stands for Forrest Mars, who is the son of Frank Mars, the founder of Mars, and Bruce Murrie (the son of longtime Hershey President William Murrie).
In the beginning, Hershey chocolate was used. Mars agreed to work with Murrie because he could guarantee a cocoa supply despite wartime limitations.
Forrest Mars spotted chocolate-eating soldiers in southern Spain. These candies featured sugar shells that protected them from melting in warm weather.
M&M's Limited was founded in Newark, NJ. In 1958, to meet demand, it moved to Hackettstown, New Jersey.
When M&M's initially came out, they were packaged in a brown cardboard tube rather than a plastic bag.
It was once only offered to members of the armed forces. Soldiers received chocolate tubes as part of their rations.
In beginning, there were only 6 colors of M&M's: six shades of brown; yellow; orange; red; green; and violet. After that, in 1949, violet was replaced by tan.
The motto "Look for the m on every item" didn't appear until 1950, when they obtained their signature "m" stamp, to distinguish.
There were no red M&Ms from 1976 and 1987. The FDA prohibited Red Dye No. 2 at the time it was believed to be carcinogenic.