The first National Coming Out Day (NCOD) was held on October 11, 1988. It was founded in cooperation with Robert Eichberg, a psychologist and personal growth leader from New Mexico, and Jean O'Leary, a political leader, ex-nun, and then head of the National Gay Rights Advocates from Los Angeles.

Some great articles are already out about what various factions and people are doing for 2015's celebration:

Celebrities Come Out for Equality in 2015

National Coming Out Day Resources
Coming out - whether it is as lesbian, gay, bisexual, transgender, queer or allied - STILL MATTERS. When people know someone who is LGBTQ, they are far more likely to support equality under the law. Beyond that, our stories can be powerful to each other.

In honor of National Coming Out Day, HRC honors all who have come out as LGBT or as a straight ally for equality... that takes bravery, and we commend you.

Every person who speaks up changes more hearts and minds, and creates new advocates for equality.
So do you have a special story to share about how, when, where, and why you came out of the closet?