This is the greatest speech ever given. Listen to the entire 17 minutes and feel yourself carried higher and higher as this great man uses repetition of theme words and moral justice to ground his arguments.
He uses the word "freedom" 20 times. "We" is used 30 times, "our" 17 times and "you" 8 times. He mentions States and other geographic references to make his message more inclusive; "From every mountainside", "slums and ghettos of our northern cities".
Dr. King uses metaphors to highlight contrasting concepts like "rise from the dark and desolate valley of segregation to the sunlit path of racial justice." He does it over an over.
Or don't pay attention to any of that and just experience the moment in 1963, before the Civil Rights Act was passed, when segregation was a part of American life, when blacks and whites could not co-mingle and dogs were allowed to attack peaceful marchers. Think of the time and the power of a man like Martin Luther King, Jr.