The Times’s findings raise new questions about Mr. Trump’s refusal to release his income tax returns, breaking with decades of practice by past presidents. According to tax experts, it is unlikely that Mr. Trump would be vulnerable to criminal prosecution for helping his parents evade taxes, because the acts happened too long ago and are past the statute of limitations. There is no time limit, however, on civil fines for tax fraud....

What emerges from this body of evidence is a financial biography of the 45th president fundamentally at odds with the story Mr. Trump has sold in his books, his TV shows and his political life. In Mr. Trump’s version of how he got rich, he was the master dealmaker who broke free of his father’s “tiny” outer-borough operation and parlayed a single $1 million loan from his father (“I had to pay him back with interest!”) into a $10 billion empire that would slap the Trump name on hotels, high-rises, casinos, airlines and golf courses the world over. In Mr. Trump’s version, it was always his guts and gumption that overcame setbacks. Fred Trump was simply a cheerleader....

Certainly a handful of journalists and biographers, notably Wayne Barrett, Gwenda Blair, David Cay Johnston and Timothy L. O’Brien, have challenged this story, especially the claim of being worth $10 billion. They described how Mr. Trump piggybacked off his father’s banking connections to gain a foothold in Manhattan real estate. They poked holes in his go-to talking point about the $1 million loan, citing evidence that he actually got $14 million. They told how Fred Trump once helped his son make a bond payment on an Atlantic City casino by buying $3.5 million in casino chips.

But The Times’s investigation of the Trump family’s finances is unprecedented in scope and precision, offering the first comprehensive look at the inherited fortune and tax dodges that guaranteed Donald J. Trump a gilded life. The reporting makes clear that in every era of Mr. Trump’s life, his finances were deeply intertwined with, and dependent on, his father’s wealth.