Washington (CNN) President Donald Trump, like his predecessors in the Oval Office, has periodically turned to history. Unlike presidents of the past, his grip on the decades before his inauguration appears, at times, tenuous or non-existent.

"History and culture -- so important," Trump said Wednesday during a speech at the American Legion's convention in Reno, showing a reverence for the past at a speech for one of the nation's largest veterans organizations.

The reverence Trump expressed for history on Wednesday was a sharp turn from his past comments, which have prompted questions about his grasp of history.

In the nearly seven months since his inauguration, the President has revived a widely debunked story about a general killing Muslim extremists by shooting them with bullets dipped in pig's blood, suggested that Andrew Jackson was "really angry" about the Civil War, which began nearly two decades after his death; has spoken of Frederick Douglass as though he were still alive; and referred to human trafficking as "a problem that's probably worse than any time of the history of this world," seemingly ignorant of African slave trade.

"He doesn't see any need to learn from anybody else in history or contemporaneously," Peter Wehner, a former speechwriter for President George W. Bush, said of Trump. "There obviously have been people with healthy egos who have been president -- you don't become president unless you have one -- but there's never been anybody who's been as staggeringly ignorant of policy and history."

The White House did not respond Saturday afternoon to CNN's request for comment.

Guided by the past

Each past president has engaged with historical tomes, and venerated their political heroes, to different degrees. Two past presidents -- Theodore Roosevelt and Woodrow Wilson -- served as leaders of the American Historical Association. And President John F. Kennedy, according to historians, read Barbara Tuchman's "The Guns of August" about the origins of World War I, which helped him navigate the Cuban Missile Crisis.

"I think that most presidents have a pretty good sense of where they locate themselves in the American tradition. They've spent some time thinking about the past, and they've spent some time reading history," Jeff Shesol, a former speechwriter for President Bill Clinton, said in an interview. "They may not know in advance of the presidency where they're going to end up in history, but I think they have a sense of who their role models are, where they fit in the larger story of American history, what they connect to."

Clinton, Shesol said, was a voracious student of history, who "really understood himself to be in the tradition of the reformist presidents" and had "a sense" of what elements of the new frontier of John F. Kennedy made sense for him ... and which aspects of Lyndon B. Johnson's Great Society needed to be fought for and preserved."

President George W. Bush was a devoted student of Lincoln -- Wehner said he used to bring historians to the White House to meet with Bush so he could learn from them -- and he engaged in a reading competition with adviser Karl Rove to see who could read more books in a year.

During his campaign for the White House and throughout his presidency, Barack Obama routinely made references to Abraham Lincoln. At times, he seemed to use the bully pulpit of his office to deliver history lessons to the nation, particularly in the ways in which he embraced and addressed the Civil Rights movement. Obama also had regular dinners with some of the nation's leading historians, including Doris Kearns Goodwin, Robert Caro and Douglas Brinkley. The dinners, Brinkley said, focused not on the present, but on the past.

"I would talk about Theodore Roosevelt and conservation or Doris Kearns Goodwin would talk about Lyndon Johnson and civil rights," said Brinkley, an author and CNN presidential historian. "Here was a president not only reading books about American history, but trying to learn from them."

While not every president is as dedicated a student of history, Sheshol -- the former Clinton speechwriter -- said, "all of them have engaged with it to some extent and have some kind of relationship with it."

Several historians who have studied the presidency extensively said they are concerned that Trump seems to view his lack of interest in reading as a badge of honor, and that lack of connection with history goes far beyond the anti-intellectualism displayed by some past presidents.

In two different interviews with Fox News hosts, Trump described himself as someone who "loves" reading but is often without the time.

"I would love to sit down and read a book, but I just don't have the time anymore," Trump told the former Fox News host Megyn Kelly in a May 2016 interview.

In March 2017, weeks into his first term, Trump told Fox News' Tucker Carlson that he doesn't get to read "very much" but was reading a book on Andrew Jackson.

"Actually, I'm looking at a book, I'm reading a book. I'm trying to get started," he said. "Every time I do about half a page, I get a phone call that there's some emergency, this or that."

Brinkley, the CNN presidential historian, described Trump as "history illiterate," asserting that the President has done "zero reading" into major American events.

"He's proud, he tells people that he doesn't read books, and it's been showing by the outlandish conspiracy theories he peddles in and misstatements that seem to almost pour out of him about the past," Brinkley said.

A distorted view of history

Trump's misstatements, embellishments and untruths about accepted historical fact have run the gamut.

In February during a meeting with African-American supporters, Trump said that the former slave and abolitionist Frederick Douglass "has done an amazing job" and is "being recognized more and more," suggesting that Douglass is still alive.

"Most people don't even know he was a Republican," the President said in March of Abraham Lincoln. "Does anyone know? A lot of people don't know that. We have to build that up a little more."

In May, Trump mused in an interview on SiriusXM radio with the Washington Examiner's Salena Zito, a CNN contributor, that the Civil War could have been avoided if Andrew Jackson, who had been dead for 16 years, had been around to stop it. Trump has said he admired Jackson and made a visit to Jackson's tomb earlier this year. Hours after a terrorist attack in Spain, Trump revived the widely debunked story he has previously told about a general killing Muslim extremists by shooting them with bullets dipped in pig's blood, urging his followers on Twitter to "study what General Pershing of the United States did to terrorists when caught."

"I think when you're in public office, you naturally acquire a sense of history," said Jack Rakove, a Stanford University historian. "Trump with his rejectionist attitude ... I just don't think that he has that sense of commitment to the whole infrastructure of American government."

Wehner, the former Bush speechwriter, said that in his experience at the White House, both staff and the presidents themselves would "go back and see what other presidents had said to try to learn them, to try to refine your approach to things."

Trump, he said, "in this respect and so many respects is sui generis; there's never been anybody out there, and he's paying the cost."

While an understanding -- and appreciation -- for the country's history and guiding principles may be preferred for a president, there is nothing requiring it. Asked whether she believed a connection and understanding of history was critical for this President, who has said he would run the country the same way he ran his businesses, Joanne Freeman, a Yale historian, responded with a question:

"Don't you think if someone is taking over a large business they would want to have a sense of how it was done in the past?"

This article has been updated -- with President Trump's comments in Reno, and Trump's tweet about General Pershing -- since the story initially appeared on August 19.