That is the crowd gathered at the washington monument today to remember the electrifying speech 50 years ago. We all know dr. Martin luther king was a towering force in civil rights, but he was also a... See More
That is the crowd gathered at the washington monument today to remember the electrifying speech 50 years ago. We all know dr. Martin luther king was a towering force in civil rights, but he was also a man under pressure to say the words that would change minds and lift souls. It was all written out, but did you know that the words "i have a dream" appear nowhere on those pages? His advisors said he should try something new. So how did it happen? Reporter: At the feet of abraham lincoln, they sang and they waited. Off stage the 34-year-old reverend martin luther king seemed a little tired. As he told abc news, he hoped to reach the hearts of good people of all races everywhere. As a result of this discipline, dignified yet determined protest and demand for freedom now. Reporter: But at first when king walked to the podium, he seemed restrained and read from a prepared speech. Suddenly singer jackson burst forth. I see her. I see her when her voice comes my attention is turned and i hear her say tell them about the dream, martin. Tell them about the dream. The dream, his dream. It was a refrain he had been using in speeches on the road but it was not part of the speech he had prepared for that day. His advisors told him he needed something new but suddenly -- I still have a dream. It is a dream deeply rooted in the american dream. When I heard him say I have a dream, I said oh, expletive, because we had been up and down the steps all night working on this alternate ending clie max. Advisors wyatt walker who said they all recognized that dr. King was now alive, transformed. We were all wrong. Little black boys and black girls will be able to join hands with little white boys and little white girls as sisters and brothers. I have a dream today. Reporter: So did gunny gun drum. That's him guarding the podium. It was not just for black people. It was trying to raise all people up, all mankind. So did the late civil rights leader dorothy hight. That's her in the hat. You felt it. He was taking is all in. Reporter: He ended with the words of an old hymn he used to sing. Free at last, free at last, thanks god all might, we are free at last. Reporter: On one day, one man with a dream lifting a nation on the wings of hope and history. ♪ Glory glory hallelujah ♪ ♪ glory glory hallelujah ♪ we thank you for watching and we leave you now with some of the sights and sounds of this profound anniversary. Good night. ♪ And the rockets' red glare ♪ ♪ the bombs bursting in air ♪
This transcript has been automatically generated and may not be 100% accurate.