It’s been five years since Michael Clodfelter spent three days exploring America’s bloodiest battlefield: the Meuse-Argonne in France.

“Most people don’t realize it, but this was the greatest battle in our history,” said Clodfelter, a Lawrence military historian and author. “It’s all pretty much forgotten now.”

That is why Clodfelter spent years researching and writing the book “The Lost Battalion and the Meuse-Argonne, 1918, America’s Deadliest Battle.” The book was recently published by McFarlands & Co. Inc., of Jefferson, N.C.

More than 26,000 Americans were killed (558 a week) during this World War I battle with the Germans. That was far more than the 12,281 Americans dead at Okinawa during World War II. At Gettysburg during the Civil War, a total of 7,000 soldiers from both sides were killed.

Clodfelter’s book also tells the story of Maj. Charles Whittlesey and “the lost battalion,” which was cut off for five days during the battle before finally being rescued. Other books have been written about Meuse-Argonne and Whittlesey’s battalion, but most have not combined the two stories.

A retired security officer with the Kansas University Public Safety Office, Clodfelter said he has a special interest in World War I. He calls it the first in a “poison stream” of wars and battles in the 20th century. Although interest in World War I has been revived, Clodfelter said its significance is lost on many people as the number of still-living veterans has dwindled to a few dozen.

“One of my intentions was to bring attention back to World War I,” he said.

“Meuse-Argonne” is but the latest of nine military history books Clodfelter, 60, has written. His first two books, written in the early 1970s, were personal memoirs about his experiences in Vietnam as a sergeant with the 101st Airborne Division. He served an extended tour from 1965 to 1967 before he was wounded when a punji stake (a wood or bamboo spike) impaled one of his legs. He also became an opponent of the war.

His second book, “Mad Minutes and Vietnam Months: A Soldier’s Memoir,” has been his biggest seller at 50,000 copies.

“On a personal level, the books kind of got rid of my demons,” Clodfelter said.

His 1998 book “The Dakota War” is about U.S.-American Indian battles with the Sioux on the northern Plains. Other books have included detailed military casualty statistical reference works.

Clodfelter writes his books for the public and for military scholars. A big part of his research is traveling to the battlefields and territories he’s writing about. During his trip to the still-undeveloped Meuse-Argonne battlefield in 2002, Clodfelter found the landscape still shows signs of the Great War. Depressions show where trenches and foxholes were. Few people visited the site while he was there.

“The most surprising thing to me was the feeling of isolation,” he said. “Americans (tourists) don’t know about it.”