Duke’s Mayonnaise can trace its roots to 1917 in Greenville, South Carolina. Founder Eugenia Duke developed a recipe for mayonnaise to add to sandwiches she sold to soldiers fighting in World War I. Eventually, the sandwich shop became an independent business – the Duke Sandwich Company – and Duke’s mayonnaise continued to be produced by new owner C.F. Sauer Company. Nearly 100 years later, C.F. Sauer Company is suing Duke Sandwich Company over alleged trademark infringement and trademark dilution. C.F. Sauer’s lawsuit claims other causes of action, including unfair competition, which fall outside of the scope of this article. A Foundation in Trademark Law The Lanham Act protects…