Which of these candy-coated chocolate buttons brand is American?

M&M's (stylized as 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 candy originated in the United States in 1941, and M&M's have been sold in over 100 countries since 2003.

Source: Wikipedia