In the late 19th century, R.T. Davis purchased a struggling milling company that put out a ready-made pancake mix branded with an older, matronly black woman in an apron and kerchief. Aunt Jemima's appearance on the package implied long hours in a southern kitchen and an authentic, homey product. The actual pancake mix reportedly did not live up to that image, but Davis bolstered his new brand by bringing Jemima to life: Davis hired Nancy Green, a former slave, to portray Aunt Jemima in ads and at events.

Green made her public debut in character at the 1893 World's Columbian Exposition in Chicago, where she charmed the crowds and doled out pancakes from a booth. The Jemima brand soon became so popular that Green had a lifetime contract with Davis and the company was renamed the Aunt Jemima Mills Company.

By then, the Aunt Jemima character had gotten so recognizable that a number of companies had co-opted the name and the image to push their own products — everything from flour to cake mix, corn meal and pancake syrup. Finally, Davis had no choice but to take his imitators to court. In 1915, the Aunt Jemima Mills Company filed a suit against Rigney and Company, which manufactured pancake syrup. While the case immediately dealt with breakfast foods, it would have large implications for trademark law in the U.S.

Rigney and Company used the Aunt Jemima name and an image similar to Green's portrayal of the character to sell pancake syrup. Davis' lawyers argued that Rigney's use of the character "created in the minds of purchasers the belief that the said goods are a product of the plaintiff." To us, the case is a clear-cut trademark violation. At the time, though, the Aunt Jemima Mills Company was really going out on a limb. Prior to this case trademark infringement happened when another company was selling the same product under the same name. Lawyer Harry D. Nims explained it like this in a 1922 issue of advertising magazine Printer's Ink:

Perhaps 15 years ago, it would not have occurred to an attorney to attempt to stop such a use of trademark because it would have been said that it was absurd to suppose that a person seeking pancake flour would buy a can of syrup and be satisfied. Recently the business world has come to realize that such an act as that of that syrup company was an attempt to appropriate the goodwill, the popularity, the celebrity of the Aunt Jemima Mills Co. and pay nothing for it, the business world has come to see that the owner of the goodwill in Aunt Jemima pancake flour may be most seriously damaged by the sale of an inferior "Aunt Jemima syrup."

The judge sided with the Aunt Jemima Mills Company and ruled that, while the pancake flour and pancake syrup were not the same product and did not compete with each other, they were related in their uses and consumers could be misled to think they were made by the same company.

The case set a precedent, known as the “Aunt Jemima Doctrine,” that's come into play pretty regularly with mixed results. The cases of University of Notre Dame v. Notre Dame cheese, Bulova watches v. Bulova shoes and Alligator raincoats v. Alligator shoes all resulted in the brands being allowed to coexist. Spam the canned meat product and spam the unsolicited email also carried on separately after the EU denied Hormel's application to trademark the generic email term.

A notable decision in the other direction happened in the 1988 trial of McDonald's Corporation v. Quality Inns International, Inc. At the time, Quality Inns was developing a chain of inexpensive hotels that they wanted to call "McSleep Inns." McDonald's cried foul charging trademark infringement, based on the prefix Mc-. Quality Inns cited the Aunt Jemima Doctrine and argued that there was little to no chance of confusion between the hotel and restaurant brands. The judge disagreed, explaining that the prefix had become so tied to the McDonald's brand that there would be consumer confusion. Quality eventually settled on Sleep Inns for the name of their new chain.