3 Musketeers candy got its name because it used to come with 3 flavors!

The 3 Musketeers candy originally came divided into three pieces. Each piece was a different flavor: one vanilla, one strawberry, and one chocolate. The candy is made by Mars and was introduced by the company in 1932. 

Although, the company no longer sells the 3-flavored bar, they offer their 3 Musketeer bar in mint and also as a double crisp bar. To make their classic bar now, they use just their chocolate nougat. The nougat starts out in huge slabs, and then they cut it into the right size for the bars. They then finish off the bar by coating it in a layer of milk chocolate. 

The bars are made in Chicago, Illinois, Elizabethtown, Pennsylvania and Newmarket, Canada. And, if you ever wondered what a nougat actually is, you’re in luck. A nougat is made with whipped eggs and sugar syrup. A flavoring can also be added. The end result is a frothy, soft candy filling that makes up the insides of a 3 Musketeers candy.

(Source)