A dream unrealized for African-Americans in Chicago

"We have come to our nation's capital to cash a check," Martin Luther King Jr. told the rapt throng on the National Mall 50 years ago.

King told the gathering of 250,000 people, most of whom were black, that the Constitution and Declaration of Independence were a promissory note "to which every American was to fall heir. This note was a promise that all men, yes, black men as well as white men, would be guaranteed the unalienable rights of life, liberty, and the pursuit of happiness."