Sen. Barack Obama's recent speech on patriotism at the Truman Memorial Building in Independence, Mo., stands in sharp relief to Frederick Douglass' Fourth of July oration before the Rochester Ladies' Anti-Slavery Society in 1852. The two men's remarks, touching on loyalty, race and the country's moral foundation, underscore the difference 150 years has made in the life of our nation.

Douglass, an abolitionist who escaped from a slave plantation, spoke on America's 76th birthday, a decade before the Civil War. He extolled the virtues of the Declaration of Independence — which he called the ring-bolt to the chain of America's destiny. The principles in the Declaration, Douglass asserted, are "saving principles."

"Stand by those principles," he exhorted his overwhelmingly white audience. "Be true to them on all occasions, in all places, against all foes, and at whatever cost."

Douglass praised the Founders as statesmen, patriots and heroes who looked beyond their day to seize eternal values. "With them, justice, liberty and humanity were 'final,' " Douglass said.

But even as he noted America's celebration of freedom, Douglass called attention to the presence of millions of enslaved blacks on American soil. He asked the assembled: "What have I, or those I represent, to do with your national independence?"

"The rich inheritance of justice, liberty, prosperity and independence bequeathed by your fathers," Douglass said, "is shared by you, not by me. The sunlight that brought life and healing to you, has brought stripes and death to me."

This July Fourth, Douglass declared, "is yours not mine."

Looking at Independence Day from the slave's perspective, he said, he did not hesitate to declare, "with all my soul, that the character and conduct of the nation never looked blacker to me than on this 4th of July."

His speech confronted dark truths: that there was an immeasurable difference between free whites and blacks in chains; that the blessings his audience enjoyed were not enjoyed by all Americans.

"You may rejoice," Douglass lamented. "I must mourn."

A century and a half later, as Americans prepared to celebrate the nation's birth, Barack Obama took the podium in Independence.

Although generations apart, Douglass and Obama have common characteristics.

Both are of mixed race. Like Douglass, Obama grew up without the steadying hand of a father.

Both men sought life's fortunes far from their places of birth. And in their speeches on independence and patriotism, both cited the courage and wisdom of the men who sought total separation of the colonies from the crown.

Obama's speech, "The America We Love," lauded the men of Lexington and Concord who launched the American Revolution. Obama also agreed with Douglass on the significance of the founding documents and the idea of liberty as a God-given right worth dying for.

But while Douglass noted his estrangement from America's experiment with democracy, Obama claimed America as his own and the Fourth of July as a time to rejoice.

His remarks showed how his context for viewing America differs sharply from Douglass'.

The putative Democratic presidential nominee spoke of always taking his "deep and abiding love for this country as a given." He said patriotism starts for him as a "gut instinct, a loyalty and love for country rooted in my earliest memories."

Obama said that as he got older, that instinct, "that America is the greatest country on earth — would survive my growing awareness of our nation's imperfections."

Racial strife, poverty and the political corruption revealed by Watergate, Obama said, were outweighed by the "joys of American life and culture, its vitality and its freedom."

Patriotism, he said, is "more than loyalty to a place on a map or a certain kind of people"; it is loyalty to American ideals and their proven capacity to inspire a better world.

Perhaps the most sobering aspect of Obama's speech on the eve of the nation's birthday was his need to defend his patriotism at all.

It makes you wonder how Independence Day orators 150 years from now will look back upon this Fourth of July.

What will they make of freedom-loving people who, at the dawn of America's fourth century as a nation, question the patriotism of a U.S. senator because he doesn't wear a flag pin in his lapel or because he has a name that doesn't sound like theirs?

What will they say about our professed fidelity to religious freedom when they find out that many of the Americans who thank God for their religious liberty are also ready to turn their backs on a candidate if they think he is a Muslim or Mormon?

Or because he's black?

What, come to think of it, would Frederick Douglass think?

Colbert I. King is a columnist for The Washington Post.