There is evidence that ancient South American Inca Indians were the first to grind peanuts to make peanut butter. In the United States, Dr. John Harvey Kellogg (of cereal fame) invented a version of peanut butter in 1895. Then it is believed that a St. Louis physician may have developed a version of peanut butter as a protein substitute for his older patients who had poor teeth and couldn’t chew meat. Peanut butter was first introduced at the St. Louis World’s Fair in 1904.
Peanuts and peanut butter became an integral part of the Armed Forces rations in World Wars I and II. It is believed that the U.S. army popularized the peanut butter and jelly sandwich for sustenance during maneuvers in World War II.