Updated: Sep 29, 2018
A business acquires rights to a trademark in one of two ways: (1) by being the first to use the mark in commerce; or (2) by being the first to register the mark with the U.S. Patent and Trademark Office ("PTO").
First to use the Mark in Commerce
The use of a mark means the actual sale of a product to the public with the mark attached. Thus, if I am the first to sell "Lucky" brand bubble-gum to the public, I have acquired priority to use that mark in connection with the sale of bubble-gum. This priority is limited, however, to the geographic area in which I sell the bubble gum, along with any areas I would be expected to expand into or any areas where the reputation of the mark has been established. So, for example, if I sell pizza in Boston under the name "Broadway Pizza," I will probably be able to prevent late-comers from opening up a "Broadway Pizza" within my geographic market. But I will not be able to prevent someone else from opening a "Broadway Pizza" in Los Angeles.
Register the Mark with the U.S. Patent and Trademark Office ("PTO")
The other way to acquire priority is to register the mark with the PTO with a bona fide intention to use the mark in commerce. Unlike use of a mark in commerce, registration of a mark with the PTO gives a party the right to use the mark nationwide, even if actual sales are limited to only a limited area. This right is limited, however, to the extent that the mark is already being used by others within a specific geographic area. If that is the case, then the prior user of the mark retains the right to use that mark within that geographic area; the party registering the mark gets the right to use it everywhere else. So, for example, if I register the mark "Broadway" in connection with the sale of pizza, the existing "Broadway Pizza" in Boston retains the right to use the name in Boston, but I get the right to use it everywhere else.