It is amazing the number of search hits this blawg gets for March Madness as a trademark this time of year. In order to keep up with the demand, below is a post from a couple of years ago that might be of interest. In addition to the information below, also see Wikipedia.
Is "March Madness" considered a trademark? The short answer is yes, as decided by the United States District Court for the Northern District of Texas, Dallas Division in 2003. There is actually a class of registered trademarks owned by the March Madness Athletic Association. Who is that you ask? The MMAA is actually a holding company formed by the NCAA and the Illinois High School Association. Sound like an odd combination? Apparently, the IHSA has used the term "March Madness" since 1939 for a state high school basketball tournamnent. For a full history of the term as used by the IHSA, visit the History of March Madness page of the IHSA web site. The NCAA has been using the mark for nearly 25 years.