The Smithsonian faces a deadline to show Trump its plans for exhibitions to mark America’s 250th birthday.

WASHINGTON (AP) — The Smithsonian Institution faced a deadline Tuesday to detail its plans to celebrate the country’s 250th birthday, part of President Donald Trump’s sweeping effort to remove negativity from the stories Americans tell about their history.

Trump has previously threatened to fund the Smithsonian if it continues to promote what he sees as “divisive narratives.” A cornerstone of American culture, the institution operates 21 museums and zoos that are among Washington’s most popular tourist destinations.

He watches: Citizen historians document Smithsonian exhibits under White House oversight

By Tuesday, the Smithsonian was supposed to provide lists of all exhibits, objects, wall texts and other materials dedicated to this year’s anniversary and other purposes. The intention is to ensure that Americans get an optimistic account of the country’s history, not one burdened by complexities or shameful events of the past.

The ultimatum was set out in a December 18 letter to Smithsonian Institution Secretary Lonnie Bunch III from White House Budget Director Russell Vaught and Domestic Policy Director Vince Haley.

Pressure mounting

“We want to make sure that no Smithsonian museum leaders are confused about the fact that the United States has been among the greatest forces for good in the history of the world,” the letter said.

“Americans will have no patience for a museum that is ashamed of America’s founding or uncomfortable with conveying a positive view of American history, one that justifiably takes pride in our country’s accomplishments and record.”

Read more: Trump amplifies attacks on ‘out of control’ Smithsonian museums for including negative parts of American history

The Smithsonian Institution is not a federal entity but receives the majority of its funds from Congress.

The White House had initially requested all relevant materials in September, but said the documents the Smithsonian handed over fell far short of what it requested.

In his executive order in March, Trump claimed that there had been a “concerned and widespread” effort over the past decade to rewrite American history by replacing “objective facts” with a “distorted narrative driven by ideology, not fact.”

As part of this, Vice President J.D. Vance was appointed to the Smithsonian’s Board of Trustees to oversee efforts to “remove unsound ideology” from all areas of the institution.

The Smithsonian Institution and the White House did not respond to requests for comment Tuesday afternoon.

Reshaping America’s Story

The prospect of polishing the historical record to please the president is a concern to many who study the past.

“History is about evidence,” said Matthew Delmont, a history professor at Dartmouth College. “It’s about welcoming complexity and nuance. It’s not about crafting one story that has to make everyone feel happy.”

“This is our history. This is our shared experience. We have to learn from it and never go back and try to whitewash or change anything based on our political leanings,” said Jim McSweeney, retired archivist from the National Archives.

In the months before Trump in August ordered a formal review of all Smithsonian exhibits, Trump fired the National Archives’ chief of staff and said he would fire the National Portrait Gallery’s director, Kim Saget, who maintained the support of the Smithsonian’s board of directors, but eventually resigned.

Indeed, references to Trump’s two impeachments were removed from a display of his photographs in the Smithsonian Institution’s National Portrait Gallery’s “American Presidents” exhibition, even though the text was available online.

Museums under the microscope

Administration officials have framed the accountability process as necessary work before the country marks the 250th anniversary of the Declaration of Independence on July 4, which the letter called “a unique opportunity to justify confidence in the operations of America’s leading cultural institutions.”

The Smithsonian review is just one part of Trump’s attack against a culture he considers too liberal.

Trump fired the board of the Kennedy Center, one of the nation’s leading cultural institutions, and selected a new foundation that voted to add his name to the exterior of the historic complex. In the months that followed, a number of artists withdrew from performances at the venue, some citing the name change and Trump’s involvement.

At the White House, Trump designed a partisan and self-described “Presidential Walk of Fame” featuring gilded portraits of himself and his ancestors, with plaques inscribed on what they did. It excludes Democrat Joe Biden, who is represented instead by a robotic pen symbolizing what Trump has described as the presidency in absentia.

At the time, the White House said Trump was the primary author of the paintings, which praised him as a historically successful figure and described Biden as the worst president in history and the person who brought the United States to the “brink of destruction.”