05/31/2012 11:12 am ET Updated Jul 31, 2012

"A Revolution Needed to Be Waged and a Union Needed to Be Saved"

These were the words of America's first black president, Barack Obama, as he praised those who had "left their homes and took up arms."

The occasion was a speech on the morning of May 28 at Arlington National Cemetery, during the Memorial Day commemoration of those who gave their lives in America's wars.

Interestingly, to begin with, Memorial Day wasn't all that inclusive. It began, after the Civil War, as Decoration Day, an annual ceremony at the end of May, in honor of all those who had fallen on the Union side.

By the 20th century, what had become Memorial Day had been expanded to include a tribute to honor all Americans who had died in all of the country's wars.

Clearly, as Abraham Lincoln implied in his second inaugural address, one cannot, if one is to "bind up the nation's wounds," honor the dead of one side and not those of the other side.

In commemoration ceremonies that honor the fallen on both sides, the question of the root cause of the Civil War is sublimated, for the sake of what has to be recognized as a remarkable restoration of national unity following the traumatic war of 150 years ago.

For if the ending of slavery was not the immediate cause of the war, it underlay it all, and it became its principal result: this "chattel slavery" that was "entrenched" in the U.S. Constitution, to cite the words of Sanford Levinson, was eliminated from the American canon.

I am reminded of a phrase I used in a paper in honor of a festschrift for the late Professor of History Ernest May: "The South's war, brilliantly fought, was not only a lost cause, it was a bad cause."