Martin Luther King Jr. improvised the most iconic part of his “I Have a Dream Speech.”

On Wednesday, August 28, 1963, 250,000 Americans united at the Lincoln Memorial for the final speech of the March on Washington. As Martin Luther King Jr. stood at the podium, he eventually pushed his notes aside.
The night before the march, Dr. King began working on his speech with a small group of advisers in the lobby of the Willard Hotel. The original speech was more political and less historic, according to Clarence B. Jones, and it did not include any reference to dreams. After delivering the now famous line, “we are not satisfied, and we will not be satisfied until justice rolls down like waters and righteousness like a mighty stream,” Dr. King transformed his speech into a sermon.
Onstage near Dr. King, singer Mahalia Jackson reportedly kept saying, “Tell ‘em about the dream, Martin,” and while no one will know if he heard her, it could likely have been the inspiration he needed. Dr. King then continued, “Even though we face the difficulties of today and tomorrow, I still have a dream. It is a dream deeply rooted in the American dream….” And then the famous Baptist preacher preached on, adding repetition and outlining the specifics of his dream. And while this improvised speech given on that hot August day in 1963 was not considered a universal success immediately, it is now recognized as one of the greatest speeches in American history. For more information on the 1963 March on Washington.