By Colin Woodward

For generations, historians have assumed that the Civil War took 620,000 American lives (360,000 Union; 260,000 Confederate). It was one of the first things we hear in Ken Burns’ terrific 1990 documentary about the war. And Larry David, himself a history major at the University of Maryland, even worked the number into an early episode of Seinfeld.

Elaine (trying hard to make conversation at a party): “Did you know that 620 million people died in the Civil War?”

Jerry (a bit wearily): “620 thousand.”

However, the latest issue of the journal Civil War History includes a discussion of the Civil War’s death toll. The lead article is by J. David Hacker, who is a professor of demographic history at SUNY, Binghamton. Hacker concludes, using “indirect” methods that compare census data from the 19th century, that the likely death toll of the Civil War is closer to 750,000, or even as high as 850,000.

The December 2011 issue also includes an essay by James McPherson, the Dean of American Civil War Historians, who agrees with Hacker in his conclusion that the 620,000 number is too low, especially in regards to Confederate soldiers.

Although I never doubted that the Civil War cost this country more than a half-million lives, I have always wondered where the 620,000 figure came from. Casualties are often difficult to pinpoint, especially on the Confederate side, and especially later in the war. For example, when one reads about the battle of the Wilderness, fought in May 1864, one is likely to see Confederate casualties that range from 8,500 (which seems far too low) to 11,000 or more. Hacker also raises an important point about many of the casualties from guerrilla warfare not being factored into the original 620,000 figure.

Much of what we know about Civil War casualties comes from Thomas Livermore’s classic book Numbers and Losses in the Civil War. One problem Hacker finds with Livermore’s book is that it assumes disease and accidental death affected Union and Confederate armies about equally. Hacker, however, believes that the Union had better medical resources and living conditions that might have made northern camps less deadly on average than Confederates ones. Livermore conceded that his estimates were just that: estimates. The problem for historians is reliable data.

The fact that many Confederate documents were destroyed in the Richmond fires of April 1865 has not helped historians, especially those who rely on statistical methods. We don’t have precise figures about Confederate deaths, desertion numbers, or even exactly how many Rebels served in the army. 750,000? A million? Union records are far more ample and accurate.

Hacker’s article is mostly methodological. And I’m sure those who know more about statistics might find fault with it. For example, the 750,000 deaths that Hacker cites for the Civil War seems to be had by merely splitting the difference between the more accepted 650,000 figure and a higher, albeit possible 850,000 number.

Hacker’s article, nevertheless, raises some important questions about Civil War casualties. The conflict remains the bloodiest in American history. And if Hacker and McPherson are right, it’s even bloodier than we previously thought.

Colin Woodward is a historian and archivist. He is the author of Marching Masters, Slavery, Race, and the Confederate Army during the Civil War (University of Virginia Press, 2014). He is writing a second book on Johnny Cash.