In the area known as the outer Oval Office, boxes had been brought in to pack up desks used by President Donald J. Trump’s assistant and personal aides. But documents were strewn about, and the boxes stood nearly empty. The table in Mr. Trump’s private dining room off the Oval Office was stacked high with papers until the end, as it had been for his entire term.

Upstairs in the White House residence, there were, however, a few signs that Mr. Trump had finally realized his time was up. Papers he had accumulated in his last several months in office had been dropped into boxes, roughly two dozen of them, and not sent to the National Archives. Aides had even retrieved letters from Kim Jong-un, the North Korean leader, and given them to Mr. Trump in the final weeks, according to notes described to The New York Times.

Where all of that material ended up is not clear. What is plain, though, is that Mr. Trump’s haphazard handling of government documents — a chronic problem — contributed to the chaos he created after he refused to accept his loss in November 2020, unleashed a mob on Congress and set the stage for his second impeachment. His unwillingness to let go of power, including refusing to return government documents collected while he was in office, has led to a potentially damaging, and entirely avoidable, legal battle that threatens to engulf the former president and some of his aides.