It used to be the case that American school children would learn a poem by John Greenleaf Whittier, Barbara Fritchie, that memorialized a brave 90-year old lady of Frederick, Maryland, who legendarily waved her Stars and Stripes in defiance of the rebel horde marching through her town.

Up from the meadows rich with corn,

Clear in the cool September morn,

The clustered spires of Frederick stand

Green-walled by the hills of Maryland.

Round about them orchards sweep,

Apple-and peach-tree fruited deep,

Fair as a garden of the Lord

To the eyes of the famished rebel horde,

On that pleasant morn of the early fall<

When Lee marched over the mountain wall,

Over the mountains winding down,

Horse and foot, into Frederick town.

Forty flags with their silver stars,

Forty flags with their crimson bars,

Flapped in the morning wind: the sun

Of noon looked down, and saw not one.

That patriotic poem actually goes on to pay a handsome tribute to Stonewall Jackson, who fought at Antietam on September 17, 1862. It is remarkable that an abolitionist poet like Whittier could honor his foe in that way--especially when the issue of civil war was far from resolved. It was something remarkable in the American spirit then, and it carried us over a century of turmoil.

The National Park Service does an excellent job of interpreting the sanguinary actions on this day in rural Maryland in 1862. For a century and more, the Battle of Antietam was known as the bloodiest day in American history. Near the little town of Sharpsburg, 3,650 Union and Confederate soldiers lay dead at the end of the single day of battle. Union losses were greater, 2,100, but Gen. Robert E. Lee's Army of Northern Virginia could little afford the 1,550 gray-and butternut-clad soldiers he lost that day. Lee was forced to retreat back into Virginia. He had hoped to score a signal victory in the North in advance of the mid-term elections. A Confederate victory, Lee hoped, could bring intervention by Britain and France and put an end to the fratricidal conflict.

President Lincoln needed, desperately, a Union victory in order to issue his preliminary Emancipation Proclamation. His commanding general, George B. McClellan, wanted no part of freeing the slaves and had sternly lectured the president on his duty to stay clear of the entire issue of slavery. There were even rumblings in the Union commander's inner circle of marching on Washington and putting down the Lincoln administration and congressional Republicans. Lincoln even had to dismiss an army captain, a grandson of the famed Francis Scott Key, for disloyal talk in camp.

Although Lincoln was heartsick that Gen. McClellan failed to follow up his victory over Lee, he was determined to issue the preliminary Emancipation Proclamation warning the South that if it did not return to the Union by January 1, 1863, all slaves held in rebel states would be freed as an act of military necessity. Lincoln acknowledged, virtually every Northern political figure acknowledged, that without rebellion against the national authority, a president would never have had such authority to deprive Americans of what state law recognized as property in slaves. Only actual rebellion made this momentous move possible.

I was taught that the Battle of Antietam was the "bloodiest day in American history." And so I taught my students. Pearl Harbor deaths came close to this dread toll--at 2,402. And now, we reckon those lost on September 11, 2001 as nearly as catastrophic a toll--2,977.

There will be speeches and lectures, re-enactments and moments of silence at the Antietam Battlefield today. This amazing site is preserved almost as it was that September morning. The whitewashed Dunker church still dominates the hilly landscape. Irony of ironies, that German pacifist sect came to quiet Maryland to get away from Europe's interminable conflicts. But here they were, their sparsely furnished house of worship being used as a field hospital. The groans of the dying would ever be remembered by the singers of hymns.

Several years ago, while living at the Naval Academy, I had to break off a writing assignment to attend a parade of Midshipmen on a Friday afternoon. The flags snapped happily in the breeze then. The bands played. On the Severn River, brightly colored spinnakers on sailboats--Navy blue and gold--billowed in the wind. The Brigade of Midshipmen marched by where my Captain wife and I sat in the reviewing stands.

They come from every state and several foreign lands. They are young and fit and mostly happy. Marching nine abreast, it took eleven minutes for the brigade to pass in review.

Suddenly, it dawned on me: The Brigade of Midshipmen that marched past us was about 3,000. Seeing them, I could visualize for the first time the 3,288 lives taken in America every day by abortion.

This day is an important day, to be sure, and it deserves to be memorialized by speeches, songs, and prayers. It marked an important crossroads of freedom for our republic. But the daily slaughter of innocents needs to be better understood and appreciated. The loss to our nation of 3,288 human lives every day has been made legal by a Supreme Court every bit as willful and power-driven as the one that legitimized human bondage in 1857.

Lincoln opposed slavery because of its inherent wrong. "Nothing stamped in the divine image was sent into the world to be trod upon and imbruted," he said with rare passion in the years leading up to the Civil War. Our question to President Obama every day must be: "Mr. President: Are not unborn children so stamped?"