The correct answer to this open question is the following.
The point about change that Martin Luther King, Jr. was making by telling the story of "Rip van Winkle" was the invitation to the African American community to "wake up" of the slumber they were in and start to manifest in the streets and to participate in the activist's civil rights actions to the demand equal rights..
The story of "Rip van Winkle" was written by Washington Irving in 1819. It refers to a man in colonial times called Rip van Winkle who slept for 20 years and when he wakes up, everything had changed. He didn't know that the colonies were independent by winning the Revolutionary War.