People had been chewing gum for thousands of years before inventors like William F. Semple, John B. Curtis, or Thomas Adams lived. The ancient Greeks munched on chewed mastic gum, or mastiche, (pronounced "mas-tee-ka"). They made it with sticky resin obtained from the bark of the mastic plant, a shrub-like tree. The ancient Maya chewed sapodilla tree sap – the same chicle used in modern chewing gum. Humans probably always have had the urge to chew to keep their mouths moist when no water was available, or, psychologists think, because it brings back memories of nursing when they were infants.

Ohio can claim credit for an invention with global impact because Semple got the first patent on chewing gum. It was U. S. patent 93,304, issued on December 28, 1869. A patent is a document, granted by the government, which gives the inventor right -- for a limited period -- to stop others from making, using, or selling the invention without the inventor’s permission. Patents cover products or processes that work in new ways or have new features. They involve how things work, what they do, how they do it, what they are made of, and how they are made.

A patent officially makes an invention the inventor's property. Like any other kind of property, the inventor can sell the patent to someone else or "rent" it. Renting out a patent is called "licensing" it. The owner charges a fee – a royalty – for others to use the patent so they can make and sell a product.

Remember that a patent doesn’t automatically stop others from using the invention. It just gives an inventor the right to sue others who do, in a so-called "patent infringement" suit.

Semple's patent became a milestone in chewing gum history, an official record of his role. Because it was the first for chewing gum, the patent makes it convenient for people to identify Semple as chewing gum’s inventor. We don’t know if other chewing gum pioneers ever paid Semple royalties to use ideas in U. S. Patent 93,304.

Inventors often tweak the technology in an existing patent, making changes and improvements that allow them to get their own patent. The huge majority of new patents granted each year are for small improvements in existing technology. In science and technology, the wheels of progress turn a fraction of an inch at a time, and innovation usually is evolution rather than revolution.