When he first took the national stage, with his electrifying keynote address at the Democratic National Convention in the summer of 2004, Barack Obama, then an Illinois state senator, briefly summarized his unusual life story, with its biracial themes and trans-continental setting. "I stand here knowing that my story is part of the larger American story," he said, adding: "In no other country on earth is my story even possible."

That story, of course, would become even more astonishing, and profoundly American, four years later, when its teller would be elected president of the United States. But the first time Obama related his life story -- and in the greatest detail -- was with the publication of his 1995 memoir, Dreams From My Father: A Story of Race and Inheritance.

The book, which won wide critical acclaim and rose to No. 1 on the New York Times bestseller list, recounted the complex tale that is by now familiar to most Americans: the young Obama's racial confusion as the son of a white mother from Kansas and a dark-skinned, absentee father from Kenya; his mother's remarriage to, and eventual split from, the boy's Indonesian stepfather, with a spell in a Muslim school in Jakarta; the boy's rearing by white grandparents in Hawaii, who sent him to a private school there; his journeys through Occidental College and Columbia University, marked by a shifting intellectual worldview and numerous romances, some of them inter-racial; his path-breaking stint as the first black editor of the Harvard Law Review; and his exploits as a community organizer and Chicago lawyer with a deepening interest in politics.

In the introduction, Obama openly admitted changing some people's names and compressing both characters and chronology, mostly for the sake of narrative flow. Over the years, the president’s biographers have made inroads piecing together which characters were based on which real-life individuals, and which events were compressed or conflated.

That process has now reached a kind of zenith, with the publication last month of Barack Obama: The Story, a deeply researched, 600-page study of the president's ancestry and early life by Pulitzer Prize-winning historian and Washington Post editor David Maraniss. The result reflects the hyper-scrutiny that attaches to our chief executives. It also offers a window into how much of the life story of this self-made man may have been made up.

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By some counts, The Story presents more than three-dozen instances of material discrepancy where Dreams fails to align with the facts as Maraniss reports them. Case in point: Maraniss confirmed that Mr. Obama's mother, Ann Dunham, left his father, Barack Obama, Sr., a volatile bigamist, and not the other way around, as related in Dreams.

Dreams also related the tale of Obama's paternal grandfather, Hussein Onyango, who was said to have been detained and tortured in a prison outside Nairobi for six months because of his brave defiance of British colonialists. But after a half-dozen interviews and other research, Maraniss deemed the tale "unlikely."

Maraniss did not respond to several calls requesting an interview, but Fox News caught up with him outside a Washington book signing. "I think there's a difference between a memoir and the serious, rigorous factual history of a biography," he said. "Some of what he did was the result of mythologies that were passed along from his family, and some were for the purposes of advancing themes in his book which had more to do with finding his racial identity."

In an Oval Office interview prior to the publication of The Story, Maraniss handed the president a copy of Maraniss's introduction, which conveyed the degree to which The Story would be challenging various scenes in Obama's memoir. The president confirmed Maraniss's research and offered sometimes guarded explanations for those instances when he had chosen to employ an approach in Dreams that was less than strictly factual.

Still, Maraniss never accuses the president of having fabricated anything or of having lied to his readers. "I consider his book very valuable in terms of understanding his interior dialogue, his struggle that he went through," the author told Fox News.

Gerald Early, a noted professor of English literature and African-American studies at Washington University in St. Louis, agreed. "It really doesn't matter if he made up stuff," Early told Fox News. "I mean, after all, it's like you going to a psychiatrist and you make up stuff, and the psychiatrist can still psychoanalyze you because they're your lies."

David Remnick, the editor of The New Yorker magazine and author of a previous biography, The Bridge: The Life and Rise of Barack Obama, published in 2010, judged Dreams to be "a mixture of verifiable fact, recollection, recreation, invention, and artful shaping." Remnick concluded that Author Obama wanted his life story to fit into a long tradition of African-American literature: a "narrative of ascent" discernible in early slave memoirs right up through contemporary classics like Ralph Ellison's Invisible Man (1952) and The Autobiography of Malcolm X (1965).

But Obama's early life, while sad in many respects, was too marked by privilege -- recreational drug use, a Hawaii upbringing with financially comfortable white parents, enrollment in elite private schools and universities -- to mesh neatly with the aggrieved black literature in which the young author was so well read and conversant. "Obama seems to sense this problem and, at the very start of his book, darkens his canvas as well as he can," Remnick wrote.

Maraniss confirmed this. For example, the back story offered for a composite character in Dreams known as "Regina," another black student at Occidental who helped the young Obama embrace his African heritage, Maraniss found to have been based in large part on Michelle Obama. The future president would not meet Mrs. Obama until eight years after he had left Occidental for Columbia.

And where Dreams related the story of Obama quarreling with a white girlfriend after the two attended a black theatre production in Manhattan -- a searing experience that left the author feeling more acutely estranged from white people at the time -- Maraniss found that the incident actually happened with a different girlfriend, in Chicago.

The false portrayal of the incident as having happened with Obama's white girlfriend in New York was startling to Australian native Genevieve Cook, who confirmed to Maraniss that she was that girlfriend. Cook, who provided to Maraniss the love letters she and the future president exchanged, also told Maraniss that Obama had "greatly exaggerated" in Dreams the details of another encounter between them.

Henry Ferris, the editor who helped Obama shape his rough and overly long manuscript nearly two decades ago, told Fox News he does not remember discussing with the author his use of literary license. "I was immediately struck by how talented the writer was and what an unusual story it was," said Ferris, now a vice president and executive editor at the New York publisher William Morrow. As for the departures from the facts, Ferris cautioned that it is "not uncommon" for memoirists. "I think there's the very good possibility...that what he intended to do is to protect the privacy of these people he writes about in his book."

"Autobiographies are not really good sources if you're looking for absolute complete factual accounts of someone's life," agreed Professor Early. "Autobiographies serve another kind of purpose for the person writing the book. I don't think it much matters whether Barack Obama has told the absolute truth in Dreams From My Father. What's important is how he wanted to construct his life."

Fox News' Anna Olson contributed to this report.