In the early 1900s, William Lawrence Murphy invented a bed that folded up into a wall when not in use. Murphy started the Murphy Door Bed Co., Inc. (MDBC) (plaintiff) and began selling and marketing his invention as the “Murphy bed.” In 1981 and 1982, the U.S. Patent and Trademark Office (PTO) denied MDBC’s applications to register “Murphy bed” as a trademark. The PTO found that the name had become generic as the public had long used the term Murphy bed as a synonym for any bed that folds up into a wall. The Trademark Trial and Appeal Board affirmed. Interior Sleep Systems, Inc. (ISS) (defendant) began using the term Murphy bed in the marketing of its own foldaway bed. MDBC brought suit for common law trademark infringement. The district court ruled in favor MDBC, finding that the term Murphy bed had acquired a secondary meaning in the market. ISS appealed.