In the speech, "I have a dream", M.L. King says the following:
One hundred years later, the Negro lives on a lonely island of poverty in the midst of a vast ocean of material prosperity.
What does he mean by "lonely island" and "vast ocean", what is he referring to here?
EDIT:
I am assuming that by "lonely island" he refers to the part of the country which the negro lived in and the "vast ocean" is the white people who ignore them.