M&M's are multi-colored button-shaped chocolates, each of which has the letter "m" printed in lower case in white on one side, consisting of a candy shell surrounding a filling which varies depending upon the variety of M&M's. The original candy has a semi-sweet chocolate filling which, upon introducing other variations, was branded as the "plain, normal" variety. Peanut M&M's, which feature a peanut coated in milk chocolate, and finally a candy shell, were the first variation to be introduced, and they remain a regular variety. Numerous other variations have been introduced, some of which are regular widespread varieties peanut butter, almond, pretzel, crispy, dark chocolate, and caramel) while others are limited in duration or geographic availability. M&M's are the flagship product of the Mars Wrigley Confectionery division of Mars, Incorporated.
The candy originated in the United States in 1941, and M&M's have been sold in over 100 countries since 2003. They are produced in different colors, some of which have changed over the years. The candy-coated chocolate concept was inspired by a method used to allow soldiers in the Spanish Civil War (1936–1939) to carry chocolate in warm climates without it melting. The company's longest-lasting slogan reflects this: "Melts in your mouth, not in your hand." A traditional milk chocolate M&M weighs about 0.91 grams / 0.032 ounces and has about 4.7 kilocalories (kcal) of food energy (1.7 kcal from fat).
Forrest Mars, Sr., son of the Mars Company founder, Frank C. Mars, copied the idea for the candy in the 1930s during the Spanish Civil War when he saw soldiers eating British-made Smarties, chocolate pellets with a colored shell of what confectioners call hard panning (essentially hardened sugar syrup) surrounding the outside, preventing the sweets (candies) from melting. Mars received a patent for his own process on March 3, 1941. Production began in 1941 in a factory located at 285 Badger Avenue in Clinton Hill, Newark, New Jersey. When the company was founded it was M&M Limited. The two 'M's 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 at the time.
In the 1980s, M&M's were introduced internationally to Australia, Canada, Europe, Hong Kong, Japan, Malaysia, and the United Kingdom.
M&Ms Royals were marketed in the early 1980s with an advertising campaign that said: "Now chocolate's got a whisper of mint." They were colored pale green or brown and showed a crown rather than an M&Ms logo.
Although they were marketed and then withdrawn in the 1960s, almond-centred M&M's were available again in 1988 in limited release, with appearances only during Christmas and Easter times; they became a standard part of the product line in 1992.
Also in 1986, M&M's launched Holidays Chocolate Candies for Easter and Christmas, with the Easter candies having a bunny, chick, and egg symbols on pastel-colored shells, and the Christmas candies having pine tree, bell, and candle symbols on red and green shells; with the latter also having a special mint flavor. By 1993, the holiday symbols were replaced with the standard trademark "M".
In 1991, Peanut Butter M&M's were released. These candies have peanut butter inside the chocolate shell and the same color scheme as the other varieties. As of at least 2013, the size of the peanut butter M&M has become slightly smaller.
In 1995, tan M&Ms were discontinued to be replaced by blue. To introduce the new color, the Home Shopping Network televised a promotional video for the blue M&M. Producer Jon Watson became the first man to wear the famous blue M&M suit.
In 1996, Mars introduced "M&M's Minis", smaller candies usually sold in plastic tubes instead of bags.
In 1999, Crispy M&M's were released. They were slightly larger than the milk chocolate variety and also featured a crispy wafer center. They were discontinued in the United States in 2005 and remained available in Europe, and Southeast Asia. In January 2015, they returned to production in the United States.
In July 2001, dulce de leche M&M's were introduced in five markets with large Hispanic populations: Los Angeles, California; San Diego, California; Miami, Florida; McAllen-Brownsville, Texas; and San Antonio, Texas. The flavor never became popular with the Hispanic community, who preferred existing M&M's flavors, and it was discontinued in most areas by early 2003
In 2010, Pretzel M&M's were released. They contain a crunchy, salty pretzel center inside of the chocolate coating and are about the same size as the Peanut M&M's, but their shape tends to be more spherical.
In 2013, the M&M's chocolate bar was re-released. It was originally released in 2004 and named M-Azing.
In 2014, Mega M&M's were re-introduced. Before then, the 'Mega M&M's' had been released in 2007 promoting the Shrek movies, being dubbed "Ogre-Sized M&M's".
In 2015, Crispy M&M's were re-introduced in the United States. They had remained available continuously in Europe and Australia.
In 2016, the M&M cookie was re-introduced in the United States.
Also in 2016, the M&M's flavor vote was created in which the fans could vote for either Honey Nut, Coffee Nut, or Chili Nut M&M's. Coffee Nut was announced as the winner by Tony Hale.
In April 2017, M&M's chocolate blocks went on sale in Australia. Six varieties (milk chocolate, strawberry, crispy, hazelnut, crispy mint and almond) are available.
Also in 2017, Caramel M&M's were released in the United States.
In 2019, the M&M's flavor vote cast three new flavors: English Toffee, Mexican Jalapeño, and Thai Coconut, with English Toffee winning.
Also in 2019, Hazelnut Spread M&M's were released in the United States.