Juneteenth, the holiday that marks the end of slavery in the United States, has been celebrated at the White House each June 19 since it was enshrined into law four years ago. But on Thursday, it garnered barely an acknowledgment from the Trump administration.

Karoline Leavitt, the White House press secretary, told reporters during the daily briefing that she was not aware of any plans by Mr. Trump to celebrate the day or otherwise officially mark it.

“I’m not tracking his signature on a proclamation today,” Ms. Leavitt said of the president, who has in the past week signed proclamations commemorating Father’s Day, Flag Day and National Flag Week, and the 250th anniversary of the Battle of Bunker Hill — none of which are among the 11 federal holidays.

Ms. Leavitt acknowledged that Thursday was “a federal holiday,” but noted that White House staff had shown up to work, and thanked reporters for working. And Mr. Trump, who has often used holidays as an occasion to advance his political causes and insult critics and opponents on social media, instead mused about topics including TikTok, the Federal Reserve chairman Jerome H. Powell and his polling numbers.

Juneteenth commemorates June 19, 1865, the day when a Union general arrived in Galveston, Texas, nearly two and a half years after President Lincoln signed the Emancipation Proclamation, to finally inform enslaved African Americans there that the Civil War had ended and that all enslaved people had been freed. Months later, the 13th Amendment was ratified, abolishing slavery in the final four border states that had not been subjected to Lincoln’s order.

The lack of revelry at the White House for a holiday that has been cherished by generations of Black Americans and was enshrined in federal law by then-President Joseph R. Biden Jr. was perhaps not a surprise. Though Mr. Trump has not specifically targeted Juneteenth, since returning to office he has moved to purge the federal government of diversity, equity and inclusion initiatives and sanitize Black history — or even erase references to it entirely.