I need some information on trademark legal issues. I've come up with a tag line for my company and wanted to go ahead and create a trademark for it. After doing a search, I found that a company in Ohio used this tag line also. I'm in Texas and my business is operated locally and doesn't do business outside of my area. After doing a search in the USPTO, I found that this trademark is 'Dead' but from my understanding, just because it's not still registered doesn't mean it's free to use. I plan to have a company perform a thorough trademark search, but I'd rather not waste my limited funds on searching for a trademark with a high likelihood of being taken.
Which brings me to my questions:
What is the likelihood that this company still has legal claim to this trademark?
What is the law regarding use of a tag line that a company in another state has trademarked? In other words, is a trademark in one state protected in all states?
Thanks for any help!