You can use tm for any other brand, whether registered in one or more US states or not registered at all. Trademark rights in the USA are created by "use in commerce" or by a preemptive registration.
Therefore, if you have a federal registration (allowing you to use ?), then you already have more than enough power to prevent anyone in the entire country from using a "confusingly similar brand", i.e., something like your brand on related goods or services.
FWIW, using ? without having a federal registration is actually illegal, although there are only administrative repercussions unless you use it fraudulently.
http://www.uspto.gov/trademarks
I'm starting a clothing brand for online only I already got my ? how much is it to get ?? And some guy is trying to do his clothing line with the same same in Washington I'm in California can ? protect me and can it make him stop trying to do the same thing? He doesn't have his ?
