From Ohio History Central
Many historians credit William Finley Semple with receiving the first patent in the United States for chewing gum on December 28, 1869. This claim is false, as Toledo, Ohio, resident Amos Tyler patented chewing gum on July 27, 1869.
A doctor in Mount Vernon, Ohio, Semple made his chewing gum out of rubber. He added things like powdered licorice root and charcoal, believing that these items would help scrub the teeth, making them cleaner. He also contended that chewing gum would strengthen a person's jaw muscles. There is no evidence that Semple ever sold his gum commercially, although he probably at least had a local market for it in Mount Vernon.