Perhaps best known for his 1994 best seller "D-Day," Ambrose, 66, has put a World War II project about the Pacific on hold in favor of a new book depicting his own transformation from a left-wing demonstrator to a super patriot.
"I want to correct all the mistakes I made ... when I would tell my history classes that dropping the bomb on Hiroshima was a crime, that the Mexican-American War was nothing but a land grab and that people like Henry Ford and J.D. Rockefeller got into philanthropy to buy their way into heaven," Ambrose said in his typically raspy tone and energetic meter. "I want to tell all the things that are right about America."
When he was diagnosed with lung cancer a month ago, Ambrose, a longtime smoker, was given six months to live without treatment. He opted for experimental chemotherapy at LSU Medical Center in New Orleans.
For now, his routine hardly befits a man fighting for his life: awake before dawn, writing eight hours a day, riding his bike, walking his dog, working out at a gym. This is, after all, a man who made his mark telling stories of soldiers who stared down death and went about their work.
"After I got over the shock, the outrage, the denial, I got to thinking how lucky I've been and that it's possible I only have time to do one more book," Ambrose said in a phone interview from his beach home in Bay St. Louis, Miss., about an hour's drive east of New Orleans.
He completed 133 pages of "A Love Song to America" in his first half-month of writing, but cannot say how long the book will be.
"It depends how long I live," he said. "I've got a lot of things I want to write about."
Those close to Ambrose are not at all surprised.
"Writing history for him is the same as breathing," said Douglas Brinkley, who has worked on books with Ambrose and who took over for him as director of the Eisenhower Center for American Studies at the University of New Orleans.
On an almost daily basis throughout his career, Ambrose would write uninterrupted from 5 a.m. to 10 a.m., regardless of where he was, Brinkley said.
"I've seen him writing in motel rooms, on airplanes," Brinkley said.
Ambrose has published more than 30 books on subjects ranging from World War II to Presidents Nixon and Eisenhower, the Transcontinental Railroad and the Lewis and Clark expeditions of the American West. His research and interviews made him believe America was the greatest country on earth - a place, for all its faults, that should be celebrated for its progress, freedom and generosity, he said.
His new book will include chapters on race in America, on George Washington and on his own experience as "a Yankee in Dixie." It will touch on his personal relationships with historical figures such as Dwight Eisenhower, but won't be what he would call a memoir.
"I'm not going to write about my sex life and family life or colleagues. That's not me. I'm going to write about America."
If he does not get back to his book on the Pacific theater, his son and partner, Hugh, will likely finish it, Ambrose said.
Ambrose gives himself slim chances of beating cancer: "My doctor tells me I might make it but I think that's pie-in-the-sky, first of all because nobody's going to live forever, and second, I've seen the CAT scans."
After two chemotherapy sessions, Ambrose says he has "had no reactions, except that I'm breathing better and my energy level is up."
NBC News anchor Tom Brokaw, author of a World War II book, and former President George Bush have called Ambrose since his diagnosis and urged him to try the M.D. Anderson Cancer Center in Houston. Ambrose decided treatment in New Orleans would likely be as good and far more convenient.
Ambrose, a doctor's son from Whitewater, Wis., was a relatively unknown professor in New Orleans for about two decades before his upbeat, easy-to-read books about World War II soldiers made him a best-selling author. He spent the 1990s building his literary successes into a family industry that even includes historical tours run by another of his sons, and he founded The National D-Day Museum, opened in 2000 in New Orleans.
But Ambrose seemed to lose momentum when accusations surfaced early this year that he plagiarized passages in several books. His supporters dismissed the accusations as jealousy. Ambrose, who footnoted the passages but did not set them off in quotation marks, apologized for carelessness but otherwise stood by his work.
"I always thought plagiarism meant using other people's words and ideas, pretending they were your own and profiting from it. I do not do that, have never done that and never will," he wrote in a newspaper editorial.
With his new book, he notes, "I don't have to have any footnotes and quotations - my own memory is the only thing I need to rely on here."
With the exception of his weekly drives to New Orleans for treatment, Ambrose has stopped traveling. He has made only one public appearance since his diagnosis - a casual affair at a local restaurant last week.
He seems relieved to have so few commitments and time to focus on a project dear to him while remaining with family at his home on the Gulf of Mexico.
"There is something very liberating about being told you have a terminal illness," Ambrose said. "You can do whatever the hell you want. Who's going to criticize you? And if they do, what the hell do you care?"
By Brett Martel