Joelle Avelino NPR August 28th, 1963 promised to be a warm summer morning in Washington D.C. As the sun began to peek over the horizon, it was quiet on the National Mall. Too quiet for organizers of the historic March On Washington. "Nobody knew exactly how many people would come," recalls Norman Hill, a young activist and labor leader at the time. Organizer and transportation director Rachelle Horowitz estimated 90,000 people would be there based on the number of buses that had been chartered. By the end of the day, an estimated 250,000 people from across the country had marched on Washington and Dr. Martin Luther King Jr delivered his iconic "I Have a Dream" speech.