The I Have A Dream speech is the crown jewel of the 20th century. Given before 250,000 souls on the steps of the Lincoln Memorial, it is called the defining moment of the US Civil Rights movement. It is the speech by which all other great speeches must be measured. Its haunting rhythm towards the end of the speech has an almost musical sound and feel.
For several years prior to this speech, King had often preached the theme "The Negro and The American Dream. " And it was in the latter part of this speech that the gospel singer Mahalia Jackson yelled from the crowd for King to "tell them about the dream" and it was then he left the prepared text and slipped into the freedom of evangelical preacher. It was this passion of the moment that propels the speech from merely great to greatness.