Here's a little background on GLBT History Month from the site:
In 1994, Rodney Wilson, a Missouri high school teacher, believed a month should be dedicated to the celebration and teaching of GLBT history, and gathered together other teachers and community leaders. They selected October because public schools are in session and existing traditions, such as Coming Out Day (October 11), occur then.
GLBT History Month is endorsed by GLAAD, the Human Rights Campaign, the National Gay and Lesbian Task Force, the National Education Association, and other national organizations. In 2006, Equality Forum assumed responsibility for GLBT History Month.