First, it's not possible to copyright a slogan.
Copyrights can be obtained for things of an artistic nature. This includes, of course, poetry, films, sculptures, music, fiction, etc. But can also include things that may not necessarily seem "artistic" in the general sense of the word. Copyrights can also be obtained for advertising copy, games, software programs and blueprints, to name just a few.
It may be possible to file for a trademark for the slogan as long as it's used to indicate & identify the source of goods/services.
If we're talking about a merely informational slogan or a slogan that conveys advertising information, it's not eligible for trademark registration.
Let's take a look at what the USPTO says (and then what that actually means):
"Slogan or phrases used on items such as t-shirts...have been refused registration as ornamentation that purchasers will perceive as conveying a message rather than indicating source of the goods."
What that essentially means is that if your slogan is merely displayed on the goods themselves and is NOT identified as the source, then the USPTO will likely refuse registration. This is a tricky, gray area so seek advice should you have a slogan that you intend to use for products.
"Use of a...slogan to convey advertising or promotional information...is not service mark use."
The concept is similar to that for goods as described above. Basically, if your slogan describes your service and/or serves as advertising copy, it's not likely eligible for trademark registration. Again, this is a tricky, gray area so seek advice should you have a slogan that you intend to use for services.
After reading this it may seem impossible for any slogan to qualify for trademark protection but really that is not the case. It's all in how the slogan is used & presented. For example, both Nike's ® slogan Just Do It ® and McDonald's ® slogan I'm Lovin' It ® are Federally registered trademarks.
Shannon Moore is the General Manager for TradeMark Express. Since 1992, TradeMark Express has met the needs of their clients with comprehensive research, application preparation, attorney referrals and trademark consultation. For further details, please visit us on the web at TradeMark Express