15. The 'I Have a Dream' portion of his historic 1963 March on Washington speech was totally unscripted. Considered one of the most significant oratories in American history, that part came about on a whim. In preparing his speech for the, King never actually wrote the 'I Have a Dream' cadence and had not planned on using it. As many preachers are known to do, he had delivered versions of 'I Have a Dream' in previous speeches -- including two months earlier in a major speech in Detroit -- but perhaps felt that the soaring imagery of the passage was too much for the setting. But midway through the speech, renowned gospel singer Mahalia Jackson, who was sitting behind him, said, 'Tell them about the dream, Martin.' With that, King deviated from his prepared remarks and started 'preaching,' thus making history. At a meeting later at the White House a beaming John F. Kennedy praised King and the speech. The speech also drew the attention of the FBI, who as part of their COINTELPRO program wrote: 'In the light of King's powerful demagogic speech yesterday he stands head and shoulders above all other Negro leaders put together when it comes to influencing great masses of Negroes. We must mark him now, if we have not done so before, as the most dangerous Negro of the future in this Nation from the standpoint of communism, the Negro and national security.'