Candidate Barack Obama built his successful campaign on Americans' desire for change. But in his inaugural address Tuesday, President Obama used the word in only one sentence: "For the world has changed, and we must change with it."

Candidate Barack Obama built his successful campaign on Americans' desire for change. But in his inaugural address Tuesday, President Obama used the word in only one sentence: "For the world has changed, and we must change with it."

That was directed to the affluent nations of the world — including this one — and their obligation to help those countries struggling in poverty.

The rest of his speech was grounded firmly in the past, emphasizing the American traditions of hard work, determination, self-reliance, loyalty. It was, above all, a call to remember those characteristics that made this country the greatest in history, and to use those strengths to tackle the enormous challenges he acknowledged we now face.

"The time has come to reaffirm our enduring spirit; to choose our better history; to carry forward that precious gift, that noble idea, passed on from generation to generation: the God-given promise that all are equal, all are free, and all deserve a chance to pursue their full measure of happiness."

Obama alluded to the immigrants who came here generations ago, those who endured slavery and oppressive working conditions, and those who fought in America's wars: "For us, they packed up their few worldly possessions and traveled across oceans in search of a new life. For us, they toiled in sweatshops and settled the West; endured the lash of the whip and plowed the hard earth.

"For us, they fought and died, in places like Concord and Gettysburg, Normandy and Khe Sanh."

Those American virtues of hard work and sacrifice, Obama suggested, are needed now more than ever, and he called on Americans to embrace the work that lies ahead:

"Starting today, we must pick ourselves up, dust ourselves off, and begin again the work of remaking America."

On national security, Obama made clear his commitment to defending it:

"We will not apologize for our way of life, nor will we waver in its defense, and for those who seek to advance their aims by inducing terror and slaughtering innocents, we say to you now that our spirit is stronger and cannot be broken; you cannot outlast us, and we will defeat you."

Emphasizing the past again, he stressed America's historical reliance on its written Constitution:

"As for our common defense, we reject as false the choice between our safety and our ideals. Our Founding Fathers, faced with perils we can scarcely imagine, drafted a charter to assure the rule of law and the rights of man, a charter expanded by the blood of generations. Those ideals still light the world, and we will not give them up for expedience's sake."

It was a speech that echoed but did not pander to Lincoln, Roosevelt, Kennedy, King. It was a speech that recognized the dire situation facing the United States and the world.

But it also was a speech that said Americans have faced hardship and desperate situations before, and each time, overcame adversity to grow stronger. By summoning those qualities that served the nation so well in the past, he said, we can face whatever the future brings.

Obama's words called us all to action, but more importantly, expressed his confidence in our ability to answer that call.

Let us hope the nation is worthy of it.