Corn was of critical importance to the Native Americans called Hopi. In an area where food was often scarce, corn provided a relatively stable food supply with important nutritional value. Corn is pounded into flour and made into tortillas as well as into piki. Piki is cornbread spread into a very thin layer, almost paper thin, that is then baked in an oven.

The accidental legacy of corn flakes goes back to the late 19th century, when a team of Seventh-day Adventists began to develop new food to meet the standards of their strict vegetarian diet. Members of the group experimented with a number of different grains, including wheat, oats, rice, barley, and of course corn. In 1894, Dr. John Harvey Kellogg, the superintendent of The Battle Creek Sanitarium in Michigan and an Adventist, used these recipes as part of a strict vegetarian regimen for his patients, which also included no alcohol, tobacco, or caffeine. The diet he imposed consisted entirely of bland foods. A follower of Sylvester Graham, the inventor of graham crackers and graham bread and supporter of sexual abstinence, Kellogg believed that spicy or sweet foods would increase passions. In contrast, cornflakes would have an anaphrodisiac property and lower the sex drive.

This idea for corn flakes began by accident when Dr. Kellogg and his brother, Will Keith Kellogg, left some cooked wheat to sit while they attended to some pressing matters at the sanitarium. When they returned, they found that the wheat had gone stale, but being on a strict budget, they decided to continue to process it by forcing it through rollers, hoping to obtain long sheets of the dough. To their surprise, what they found instead were flakes, which they toasted and served to their patients. This event occurred on August 8, 1894, and a patent for "Flaked Cereals and Process of Preparing Same" was filed on May 31, 1895, and issued on April 14, 1896, under the name Granose.

The flakes of grain were a very popular food among the patients. The brothers then experimented with other flakes from other grains. In 1906, Will Keith Kellogg, who served as the business manager of the sanitarium, decided to try to mass-market the new food. At his new company, Kellogg's, he added sugar to the flakes to make them more palatable to a mass audience, but this caused a rift between him and his brother. To increase sales, in 1909 he added a special offer, the Funny Jungleland Moving Pictures Booklet, which was made available to anyone who bought two boxes of the cereal. This same premium was offered for 22 years. At the same time, Kellogg also began experimenting with new grain cereals to expand his product line. Rice Krispies, his next great hit, first went on sale in 1928.

There have been many mascots of Kellogg's Cornflakes. The most popular one is a green rooster named Cornelius (Corny) Rooster who has been the mascot since his debut. In earlier commercials he had a speaking part and his catchphrase was "Wake up, up, up to Kellogg's Cornflakes!" He was voiced by Dallas McKennon and Andy Devine. Later he stopped talking and simply crowed.