In his 1963 "I Have a Dream" speech, Dr. Martin Luther King, Jr. stated that African-Americans had been denied their Constitutional rights.
Dr. King contended that the Declaration of Independence promised all men the unalienable rights of life, liberty, and the pursuit of happiness. King claimed all African Americans actually received was a "promissory note."
So we have come to cash this check, a check that will give us upon demand the riches of freedom and the security of justice.
Further, Dr. King pointed to the "fierce urgency of Now" to make good on these promises of democracy that African Americans had been denied for nearly two centuries. Now, he declared, was the time to end "the quicksands of racial injustice."
Still, in adherence to his philosophy of non-violence, Dr. King urged the quarter of a million people present not to "allow our creative protest to degenerate into physical violence;" instead, they must carry on the struggle for Constitutional rights with "dignity and discipline." Finally, Dr. King urged the crowd not to "wallow in despair" because he had a dream that one day freedom would be given to all people in America.