It is an old problem in trademark law. Someone develops a trademark and starts using it on goods or services. Business improves and the company slowly expands into different areas of the country. Sooner or later this first user discovers that someone else in another part of the country is using the same mark on the same goods. Although the second user started using the mark after the first user, the second use was made without knowledge of the first user. The next thing you know, there is a lawsuit. In such a case, who should win?
David S. Welkowitz,
The Problem of Concurrent Use of Trademarks: An Old/New Proposal,
U. Rich. L. Rev.
Available at: https://scholarship.richmond.edu/lawreview/vol28/iss2/4