What event in U. S. History might Dr. King be referring to when he says, "the Negro's basically mobility is from a smaller ghetto to a larger one"?

Civil Rights Movement

Explanation:

This speech was important in several ways: It brought even greater attention to the Civil Rights Movement, which had been going on for many years ... After this speech, the name Martin Luther King was known to many more people than before. It made Congress move faster in passing the Civil Rights Act.

In Martin Luther King's speech, his thesis was the Negroes should rise above their persecution and that all men, women, and children should be free. This is a value claim. King's values tell him that all people, no matter what race, should be treated as equals