Paul Greenberg

What was the cause of that awful conflict? Why were Americans now fighting each other? Some said it was over different interpretations of the original Constitution: Were these sovereign states, or was their Union supreme? That question had engaged the country's leading statesmen and political theorists for decades, through one futile Great Compromise after another. But something deep in the American soul understood that men were now fighting and dying for more than a political theory.

Then what was The War about? Some said it was over the peculiar institution in the part of the Union that had separated itself from the rest, the part that stretched from Virginia to Texas, and that institution was human slavery.

But how many Southerners had rallied to the new flag because they wished to keep others enslaved? No, there had to be something more profound and less self-serving than that to explain the birth of a nation.

As the war proceeded, one bloody and momentous battle after another, it became apparent what Southerners were really fighting for -- to repel what they had come to see as an invasion. They were fighting for their land, for their home and their vision of it -- for a nation bound together by what had always bound nations together: a common history and heritage, a shared vision of the past and future. In short, the old European definition of nationality: a bond of blood and iron, Bismarck called it.

When the rebel yell rose across the battlefield, like a mounting roar from a thousand advancing hearts, there was no doubt what united Virginians and Texans and all the rest, and what they were fighting for: The South! The South! The South! And not just some abstract vision of the South but the reality of it, as real and fecund as the green, ever forgiving land itself.

Then there were those on the other side of this awful conflict. Were those who had risen to save the Union defending only some abstract constitutional doctrine about the nature of the Union? Is that why they had responded in overwhelming numbers when a president issued his call for troops and, even more impressive, had persevered in the face of one defeat after another? Just to make a constitutional point?

Or had they come to see that this is not a nation like all other nations, one based on ethnic identity, but on an idea? The idea that all men are created equal. That singular idea would make all the difference, and America exceptional. And why in the end one nation would die in birth, and another be reborn in freedom.

Long before he was president, Abraham Lincoln had pondered, in quiet solitude and clamorous debates, why Americans were so dedicated to their vision of one nation under God. Why were we so entranced by freedom, and so determined to resist what seemed the inevitable spread of slavery across the whole continent? A hundred and fifty years ago this week, at a place called Gettysburg, Mr. Lincoln would answer that question in only 272 words that compressed a lifetime of thought -- words that will live as long as does government of the people, by the people, and for the people. Call it the American Idea.

Paul Greenberg

Pulitzer Prize-winning Paul Greenberg, one of the most respected and honored commentators in America, is the editorial page editor of the Arkansas Democrat-Gazette.