M&M's were first introduced in 1941, not for the civilian market, but to provide a practical solution for the U.S. military during World War II. Inspired by Spanish Civil War soldiers eating hard-shelled chocolate pellets, founder Forrest Mars Sr. partnered with Bruce Murrie (giving the candies their name—Mars & Murrie) to create a chocolate that wouldn't melt in a soldier's hands or rations, even in tropical climates. This wartime-exclusive status secured a devoted veteran following, and the famous "Melts in your mouth, not in your hand" slogan was trademarked in 1954 to capture their unique selling point for the public.