The Aztecs also used chicle and even had rules about its social acceptability. Only kids and single women were allowed to chew it in public, notes Mathews. Married women and widows could chew it privately to freshen their breath, while men could chew it in secret to clean their teeth. In North America, indigenous people chewed spruce tree resin, a practice that continued with the European settlers who followed. In the late 1840s, John Curtis developed the first commercial spruce tree gum by boiling resin, then cutting it into strips that were coated in cornstarch to prevent them from sticking together. By the early 1850s, Curtis had constructed the world’s first chewing gum factory, in Portland, Maine.
