As President Donald Trump moves to overhaul the federal government with astonishing speed, he has wreaked havoc on one agency long known for its nonpartisanship and revered for its mission: the National Archives and Records Administration.

The independent agency and its trove of historic records have been the subject of Hollywood films and the foundation of research and policy. It also holds responsibilities in processes that are crucial for democracy, from amending the Constitution to electing a president. As the nation’s recordkeeper, the Archives tells the story of America — its founding, breakdowns, mistakes and triumphs.

Former employees of the agency now worry it’s becoming politicized.

Earlier this month, the Republican president abruptly fired the head archivist. Since then, several senior staffers at the Archives have quit or retired. An unknown number of staffers at the agency also have accepted government-offered deferred resignations, often known as buyouts, or been fired because of their probationary status.

Everything that happens in the government, domestically and internationally, generates records. The National Archives is their final landing spot.

Among those are the nation’s precious founding documents, including the original Constitution and Declaration of Independence. The collection also includes military personnel files that allow veterans to get benefits, employment and tax records, maps, drawings, photographs, electronic records and more.

The archivist of the United States is the steward of those billions of records, which belong to the American people, said James Grossman, executive director of the American Historical Association.

Besides its museum in Washington, the agency manages field offices and presidential libraries around the country. It also authenticates and certifies new constitutional amendments and houses the Office of the Federal Register, which, among other things, verifies electoral certificates during presidential elections.

The president didn’t give a public reason for firing archivist Colleen Shogan, but he has long held a grudge against the agency for notifying the Justice Department of his alleged mishandling of classified documents after he left office following his first term.

That 2022 referral led to an FBI search of his Mar-a-Lago estate in Palm Beach, Florida, and a federal indictment against him. A federal judge dismissed the case last year.

Shogan wasn’t working for the agency at the time. Still, Trump fired her abruptly on Feb. 7 without giving her a reason, she said in a social media post.

The Society of American Archivists said its leadership was alarmed by the news and said the firing with no stated cause “does harm to our nation and its people.”

The president is allowed to dismiss the head of the agency, but none has done so quite as brazenly as Trump. The closest historical precedent was in 2004, when archivist John Carlin resigned and revealed in a letter to a U.S. senator that he had been asked to do so by President George W. Bush’s Republican White House.

The president is required by law to notify Congress of the reasons for the firing, but he isn’t bound to any timeline. House and Senate leaders didn’t respond to The Associated Press’ inquiries about whether Trump had shared that information. The Senate committee that has appropriations jurisdiction over the Archives was not told of Shogan’s firing beforehand, nor has it been told of any replacement, a congressional staff member said.