From Wikipedia:

Chewing gum in various forms has existed since the Neolithic period. 5,000-year-old chewing gum made from bark tar, with tooth imprints, has been found in Kierikki, Yli-Ii, Finland. The tar from which the gums were made is believed to have antiseptic properties and other medicinal advantages.[1] The ancient Aztecs used chicle as a base for making a gum-like substance. Women in particular used this type of gum as a mouth freshener.

Forms of chewing gums were also used in Ancient Greece. The Greeks chewed mastic gum, made from the resin of the mastic tree.[2] Many other cultures have chewed gum-like substances made from plants, grasses, and resins. The American Indians chewed resin made from the sap of spruce trees.[3] The New England settlers picked up this practice, and in 1848, John B. Curtis developed and sold the first commercial chewing gum called The State of Maine Pure Spruce Gum. Around 1850 a gum made from paraffin wax was developed and soon exceeded the spruce gum in popularity. William Semple filed an early patent on chewing gum, patent number 98,304, on December 28, 1869.[4]

Modern chewing gum was first developed in the 1860s when chicle was imported from Mexico for use as a rubber substitute. Chicle did not succeed as a replacement for rubber, but as a gum it was soon adopted and due to newly established companies such as Adams New York Chewing Gum (1871), Black Jack (1884) and “Chiclets” (1899), it soon dominated the market.[5] Synthetic gums were first introduced to the U.S. after chicle no longer satisfied the needs of making good chewing gum. The hydrocarbon polymers approved to be in chewing gum are styrene-butadiene rubber, isobutylene, isoprene copolymer, paraffin wax, and petroleum wax.

One of the best known chewing gum manufacturers worldwide is Wrigley[citation needed]. Wrigley was founded by William Wrigley, Jr. in 1892 in Chicago. It was known as Wrigley’s Spearmint Gum in 1906 and within four years was the bestselling gum in the U.S. and is still the largest market for gum in the world. According to Wrigley surveys, the average American chews 300 sticks per year[citation needed]. Historically, during and after World War II, the image of an American soldier chewing a piece of Wrigley's gum became an icon in the American media[citation needed]. Wrigley began donating their gum to the troops, and it was regarded as a stress reliever and a healthier alternative to smoking[citation needed].