it was the paira to the ation. it was the coming of the dream. >> reporter: one of the narrations was that dr. king hardly looked down at his notes. he had memorized most of it. >> we will be able to feed up that day when all of our children, black men and while men, jews and catholics will be able to hold hands and we will be able to sing the spiritual, free at last, free at last, thank god all mighty, we are free at last. >> when we got to the last line, free at last, free at last, thank god all mighty, we have free at last, people just went nuts. people screamed and applauded and shouted. >> ♪ we are free at last, i do believe that we will overcome some day. ♪ >> still to come on a second look, biez in berkeley in 1964. we revisit the free speech movement. and a bit later, songs of protest and times of turmoil. san francisco 1968. our planes start flying when it's dark. and they don't stop flying until it's dark again. flying all day, every day. you deserve our best. that's why there's so many flight options