Winston Groom wrote a book one time called Forrest Gump. You might have heard of it. It got made into a movie and then a restaurant. People just thought Forrest was the best.

And while Tom Hanks' Oscar-winning turn as the titular idiot savant helped secure Groom's place in pop culture history, the book is something of an anomaly when considering the rest of his work. Most of his books have centered on war. Groom fought in Vietnam, and his Conversations with the Enemy, a Vietnam POW tale co-authored with Duncan Spencer, was a Pulitzer Prize finalist. The Alabama-native reveals a particular affinity for the Civil War, travelling backward through the conflict with historical precision in Kearny's March: The Epic Creation of the American West, 1846-1847, Vicksburg, 1863 and now Shiloh, 1862, "the first great and terrible battle of the Civil War" that just commemorated its sesquicentennial (neat word for 150 years). Groom visits the Carter Center Wed., April 11, 7 p.m. to discuss the 448-page tome.

What sparked your interest in the Civil War to the extent that you've researched and written about it in such detail?
Well you know in the South, you get sort of a heavy dose of the Civil War. I had read Bruce Catton and Shelby Foote as I grew up, and they were what I guess you would call "generalists," meaning that they covered the entire war. And I have written a lot military instances besides the Civil War, I've written about World War I, World War II, War of 1812, Mexican War, so I'm not really stuck in that Civil War history, but I have done several books on it. And in particular, in the war in the West, which hasn't been covered as much as the war in the East, meaning the fighting in Virginia, Maryland and Pennsylvania.

I think it was very important, the war in the West. For one thing, it produced General Grant. But after I had done Forest Gump, I started thinking, you know, every writer has, if you're lucky one good book in you, and if you're really lucky you have two, and if you're extremely lucky you might have three. But the light is that novelists, they keep on going because they don't know what to do and I was thinking I don't want to wind up like [F. Scott] Fitzgerald and Thomas Wolfe, drinking himself to death. Or Hemmingway, blowing his brains out. And that was not a path I wanted to go down, and I was thinking I really wanted to try my hand at history.

What do you particularly find fulfilling about digging into history, is it the learning process?
Where the hell else can you get paid for reading? It's not a bad life. As I go along, I generally have chosen, when I write, things that I don't know about as opposed to things that I do know about. As opposed to say a professor who has studied the same subject for 40 years. And I go into it as a learning experience, and I guess maybe I'm vain enough to think my observations and thoughts about how this story should be told will hold interest with other people.

There are plenty of anecdotes from things like old letters or journals used in the book. How and where did you find all the different pieces of the story?
I've always shied away from Shiloh because it was an enormously confusing battle. You had a 100,000 men trying to kill each other at once, in a day in a half, in a little piece of ground that was heavily forested and cut up by ravines and creeks - the most awful place to fight a battle as you can imagine. And I wondered if I could make sense of it.

I've been doing the Civil War backwards. I started off with Nashville in 1864 then I wrote about Vicksburg in 1863, and now Shiloh in 1862. As usual, I'm doing it backwards. And I thought that as I get into the story, the way to tell this, rather than your normal historical approach, or the approach most historians would take before me, is to try to describe this thing regiment by regiment. There were like 140 regiments fighting. It becomes very difficult when you try to do it that way. I thought I could give the reader a sense of what happened by pulling from about 20 or so narratives that were either taken by people who kept diaries or wrote memoirs or letters, that kind of thing. I think it works, it's a different approach but I thought it would be more intimate for the reader than just trying to describe a minute-by-minute blow-by-blow story of the battle. Because its unrelieved slaughter.

It does give it a very human quality. Was there one particular soldier or letter that you find most affecting or memorable?
I found the story of Josie Underwood to be very affecting, it was sad what happened to her, and it was emblematic of what was happening in households all over the nation. If you were to translate the 600,000 dead soldiers of today's population, that would be like 10 million people were killed and 60 million were wounded. And there are human dimensions to that, too. The war touched practically every household.

But you know, I was lucky, I had some very good writers at Shiloh. You had Ambrose Bierce, who was quite famous in his day, and remains famous with his The Devil's Dictionary. And Henry Morton Stanley became a very famous journalist, he was of the Livingstone fame, and he left a good record. Lew Wallace, who wrote the most famous novel of the 19th century, Ben-Hur, he was there. And you had some others who were very good writers who later became journalists, some of those people's stories, diaries, memoirs I used. It struck me as a way to tell Shiloh and break up the relentlessness of the killing.

Speaking of that relentlessness, how did the battle of Shiloh earn such an infamous place in American war history?
It was an enormous shock to the American public on both sides. The only previous battle in the war prior to that time had been the battle of Bull Run, which produced roughly 5,000 casualties. Shiloh was almost 25,000 casualties. Understanding it at that time had been that the war was going to be a short one; it was going to be decided by one big battle and be over by Christmas. And after Shiloh, everyone, including Ulysses S. Grant who subscribed to that theory, began to realize that that was not so. And they began to see that what they had unleashed by starting the Civil War was going to drench the country in blood for some years to come. And Grant came away with that notion, and he took that information with him through Vicksburg, and when Lincoln called him back East to take charge of all the armies, it changed his entire strategy, he realized this was going to be a war of attrition. He used his army like a bludgeon, it was just going to be who could take the most lives and stand it the longest. And that's the way the war played out.