The U.S. National Archives and Records Administration said on Saturday it “made a mistake” by blurring some words in a photo showing protest signs in the 2017 Women’s March.

The admission comes after The Washington Post reported Friday that the National Archives made multiple alterations to a photo of the 2017 Women’s March, blurring signs held by attendees that were critical of President Donald Trump or that contained words that referenced women’s anatomy.

The Archives, an independent U.S. agency charged with preserving and documenting government and historical records, told that it blurred the word “Trump” in signs on the photo as well as “words that referenced parts of a woman’s body.”

The image in question was part of a promotional display, not an artifact, for the Archives’ current exhibit on the 19th Amendment, which prohibits state and federal governments from denying the right to vote to U.S. citizens on the basis of sex.

“This photo is not an archival record held by the National Archives, but one we licensed to use as a promotional graphic. Nonetheless, we were wrong to alter the image,” the Archives said in a statement on Saturday.

The agency added that it “removed the current display and will replace it as soon as possible with one that uses the unaltered image.”

The Women’s March on Jan. 21, 2017, held a day after Trump’s inauguration, drew hundreds of thousands of protesters in Washington, D.C., and an estimated 3 million in cities across the country and around the world.

National Archives spokeswoman Miriam Kleiman told in an email that the agency chose photos from both the Women’s March in 2017 and a 1913 women’s suffrage march “and presented them together in a single display.”

The display attempts to show the commonality between the women’s rights demonstrations, which both took place on Pennsylvania Avenue in the nation’s capital, even though they occurred 100 years apart.

“As a non-partisan, non-political federal agency, we blurred references to the President’s name on some posters, so as not to engage in current political controversy,” said Kleiman. “Modifying the image was an attempt on our part to keep the focus on the records.”

Kleiman said the Archives also blurred words “that could be perceived by some museum visitors as inappropriate, so as not to distract from the graphic’s intended purpose.”

“The decision to do this was made during the exhibit development process by a group that included agency managers and museum staff members,” she said. “The National Archives only alters images in exhibits when they are used as graphic design components. We do not alter images or documents that are displayed as artifacts in exhibitions. In this case, the image is part of a promotional display, not an artifact.”

The American Civil Liberties Union slammed the Archives’ alteration of the image.

“The government can’t airbrush history or erase women’s bodies from it. It is the job of the National Archives to document history, not alter it to serve the president’s ego,” said ACLU Deputy Legal Director Louise Melling in a statement.

The Archives said in its statement that it “will immediately start a thorough review of our exhibit policies and procedures so that this does not happen again.”