King mentions many parts of the United States in his "I Have a Dream" speech. This is meant to be sure that his audience realizes that the entire country has made equality a dream deferred for African-Americans.
The first specific mentions begin on the third page of the speech, when he refers to "the Negro in Mississippi...and the Negro in New York" (3), the Mississippi Negro not being permitted to vote and the New York Negro feeling he has no one he can vote for. He then exhorts his audience to go back and change the situation, specifically mentioning Mississippi, Alabama, South Carolina, Georgia, Louisiana, and "the slums and ghettos of our Northern cities" (4). He wants to make clear that injustice is not simply a Southern problem, but a Northern one, too. He references Georgia and Mississippi again, saying he dreams that slave owners and the descendants of slaves in Georgia will be able to "sit down together at the table of brotherhood' (4), and that even Mississippi can be changed, into "oasis of freedom and justice' (5). He then mentions Alabama, a state with "vicious racists" (6), as being capable of being transformed into a place where black and white children can "join hands" (6).
As King wraps up his speech, with his metaphor of highs and lows, he talks about "the prodigious hilltops of New Hampshire" (6), the "mighty mountains of New York" (6-7), "the heightening Alleghenies of Pennsylvania" (7), "the snowcapped Rockies of Colorado" (7), "the curvaceous slopes of California" (7), "Stone Mountain of Georgia" (7), "Lookout Mountain of Tennessee" (7), and finally, "every hill and molehill of Mississippi" (7).
King has managed, with his references to North and South and a list that sweeps coast to coast, to make sure that his audience understands that the bell of freedom needs to ring in every part of the land and that the playing field of his metaphor is smooth, with no greater burdens for some than for others. This is a wonderfully crafted speech, and it still has great power to move today.