At its dedication, President Lyndon Johnson, on the verge of signing the landmark Civil Rights Act of 1964 and the Voting Rights Act of 1965, wanted a museum that would kindle patriotism, but he set a slightly different tone by depicting a museum that shows, borrowing the words of William Faulkner, “the agony and the sweat of the human spirit.” All these founding words and sentiments, understandably, breathed the rhetoric of Cold War triumphalism.

The report offers no context for what might have invoked such expressions: the Soviet achievement of the hydrogen bomb, Sputnik, the Korean War, the Cuban missile crisis, the March on Washington and the assassination of President John F. Kennedy. Had the Domestic Policy Council consulted trained historians, they might have provided such contexts. The report’s criticism of the use of concepts like “whiteness” in staff training, or its disdain for “land acknowledgments,” is actually a point of agreement with many academic historians.

A handful of years after the opening of the museum, there were almost 40,000 nuclear weapons in the arsenals of the United States and the Soviet Union. This frightening standoff between superpowers not only fomented McCarthyism in America, with its suppression of free speech, but according to a historian of that era, Ellen Schrecker, a “more conservative … jingoistic political culture” and a “polarizing habit of mind” across the nation.

Triumphalist history, which is exactly what the Trump White House demands, cannot tolerate nuance, ambiguity, complexity. These elements of real history — dare we say truths about human experience — always spoil the party and the military flyovers. President Trump and his supporters have instincts for history, but far too little knowledge.

The journalist and editor Tom Engelhardt, in his book “The End of Victory Culture,” showed how in the 1950s and ’60s, across popular culture, “triumphalism was in the American grain.” With children’s toys, cartoons and popular magazines, and especially at the movies, “the pleasures of victory culture” were “an act of faith.” All of us who grew up in this overweening Cold War culture of the 1950s, including and especially Mr. Trump, remember this well, with wildly different lessons.