That myth-making began when, as a young man, Mr. Trump falsely claimed to own the real estate empire still owned by his father, the legendary builder Fred C. Trump. It continued through the flashy opening sequence of “The Apprentice” and on to the campaign trail in 2015.

The first public record of Mr. Trump’s financial exaggerations came in 1976, when Mr. Trump, just few years out of college, boasted to a Times reporter that he was already worth “more than $200 million.”

To support this fantastical assertion, Mr. Trump laid claim to various buildings and projects throughout the New York City area. In truth, his father owned it all.

Years later, it emerged in a public filing that his 1976 taxable income had been only $24,594.

In the 1980s, instead of appropriating his father’s wealth as his own, he was quick to diminish his father’s considerable achievements. He consistently cast Fred Trump as a behind-the-scenes cheerleader who ran a modest collection of outer-borough apartment buildings. Mr. Trump never mentioned his father’s considerable wealth, or the financial support that made his gilded life possible. He claimed to have gotten only a $1 million loan from his father — and to have repaid it, with interest.

“He was a solid guy and a bright guy and I learned a lot from my father. In terms of support, that was the No. 1 thing I got from my father,” he told the late-night host David Letterman in 1987, oddly referring to his father, who did not die until 1999, in the past tense.