The event was inspired by last year’s Reason Rally in Washington, says Mandisa Thomas, president of Black Nonbelievers, a co-sponsor of the celebration along withBlack Atheists of America. The Reason Rally drew over 20,000 nonbelievers from all over the country to the National Mall on a rainy March day, showing a solidarity that had never before been demonstrated by America’s atheists and humanists.

“We thought it would be a great idea to have a similar event," Thomas told me in a recent interview, adding that the Blackout will be a chance to showcase both the growing numbers of secular minorities as well as pro-secular speakers and performers who may not be well known outside the African-American community.