"I have a dream that one day this nation will rise up and live out the true meaning of its creed: 'We hold these truths to be self-evident: that all men are created equal.'"
Fifty years ago today, addressing the overflow crowd at the March on Washington for Jobs and Freedom, the Rev. Martin Luther King Jr. gave his most famous speech - one of the most famous speeches in American history.
King knew he was addressing not just the people who packed the National Mall, but also the millions of Americans who were watching on television or listening on the radio. And in telling us about his dream for a better America, in putting it in such simple images, he was able to do something extraordinary.
His dream became our dream. It became a vision of the country we hoped to someday see, where people "will not be judged by the color of their skin but by the content of their character," and where black and white children will "walk together as sisters and brothers."
Remember the context of that day. The march was a massive display of what was a common form of protest. And the civil-rights leaders and ordinary citizens who marched for racial justice in American cities risked injury, jail and even death.
The presumed exercise today is to ask to what degree King's dream has come true, how far along are we on that march. And clearly, we have come a long way. The overt racism of segregated restaurants, hotels and schools is gone. But this is still a very different country for its black and white citizens, as measures of employment, income or home ownership show.
Insofar as things have changed for the better, they have done so because of the efforts of individuals who took King's message back to their hometowns and worked to make his dream a reality.
The other question people will ask today is whether we have done enough - and indeed, some who think we have done enough argue we no longer need special efforts to protect the voting rights of blacks, for instance.
But that's the wrong question. Does a musician or an athlete or a scholar ever feel that he or she has practiced enough, run enough, learned enough? King reminded us that we, as Americans, are called to perfect our craft, the art of living together in freedom and equality.
We must never stop trying to get better at that.