One summer recently, my wife and I took took a drive through the southern United States, stopping off at various sites of Civil War battles and old forts. Up through Savannah, on through the Carolinas and into Virginia and Washington, D.C. Then on to Gettysburg, with stops on the way home to tour the deadly grounds of Antietam, Fredericksburg and Chancellorsville.

At each stop, we paused and looked over the killing grounds where young men by the tens of thousands died. Nearby cemeteries spread out like a great sea, the small stones inscribed ‘Unknown.’ We looked out and were speechless.

The Civil War, of course, was a horror story. In the four years after Southern cannons fired on Ft. Sumter, more than 620,000 soldiers, Yank and Rebel, died. That would be about 2 percent of the then U.S. population – an equivalent today of 6 million lives.

As outlined in her very moving book, The Republic of Suffering: Death and the American Civil War, Drew Gilpin Faust, historian and president of Harvard, details how the sheer enormity of the scale of death and destruction came as a brutal shock to the religious and social culture of the 19th Century. The prevalent convention of the Christian ‘good death’ – to die at home amid loved ones, who would witness your last words of acceptance of God’s mystery and reassure the dying and the living alike that that death was merely a passing to Eternity – was irreparably shattered.

Faust tell us that about 40 percent of Union combat fatalities and a higher percentage of Southern were never identified. Often their remains were never located. How could a benevolent God, whom both sides fervently prayed to for victory, allow this horror on the earth? ‘How does God have the heart to allow it,’ asked Southern poet Sydney Lanier.

The armies of both sides were woefully ill-prepared for the slaughter to come. The Union army had no units trained for graves registration, no burial details, no systematic means of counting the dead or identifying them. Soldiers would write notes and pin them, sometimes with daguerreotype images to assist in identification. In the wake of great battles, wives, fathers and brothers and sisters wandered the fields of corpses, hoping to find their loved one’s body and take it home. Often, their search went on for months or years.

A cottage industry arose of entrepreneurs who, for a fee, would scour the battlefields and ship the bodies home. Other specialists brought ‘improved’ embalming techniques and and the promise of airtight coffins and set up shop amid the fields of dead. Some Nothern states and, eventually, Congress provided funds for great cemeteries near the battlefields to provide sides provide a decent burial for the soldiers who had given such a price. Until long after the war, however, they were only for the Union dead. Southerners weren’t allowed.

Faust provides ample scholarly detail to document how the war greatly affected 19th Century life. But the greater story she unfolds is the lasting effects it played on the creation of a sense of a United States.

‘Death created the modern American union,’ Faust tells us. ‘Not just by ensuring national survival, but by shaping enduring national structures and commitments.’ The war that had helped end slavery and its odious hold on America now helped create a greater sense of national purpose and obligation. Whether the nation should have elevated the end of slavery as the sacred result of the work of death in the war – and abolitionist like Frederick Douglass had certainly hoped so – the struggle to comprehend the meaning of the war’s harvest took precedence.

The dead, known and unknown, had experienced what the 19th Century termed ‘the great change.’ But they were the creators of their own destruction – both butchers and butchered But the survivors – the soldiers who experienced such horrors as this war brought, as well as thei loved ones who were left with only memories of their sons and brothers and husbands – also underwent the shock of change.

‘Individuals founds themselves in a new an different moral universe…,’ Faust writes. ‘Where did God fit into such a world?’

The nation, too, survived and found itself charged with a new and immeasurable debt for the sacrifice of those who died and suffered for its very survival. We live today with the legacy of the state’s responsibility created by the force of the dead in the Civil War, Faust says.

We owe those who we call to serve in war to care for those who die and those who survive. We owe it to their families to account for their lives and deaths. The very purposelessness of their sacrifice, she writes, created its purpose.

This is an excellent book, both morbid and hopeful. It is a very American book. Whether you are a Civil War buff or not, you will find something moving and provocative in it.