Washington (CNN) - Standing in the White House Blue Room on Tuesday, President Donald Trump expressed surprise that Susan B. Anthony, the woman's rights activist who was arrested and found guilty for voting in 1872, had never been pardoned.

"This was brought up a week ago, and I was so surprised that it was never done before," he mused, announcing he would take the step later in the day. "What took so long?"

The answer, it turns out, is that Anthony may not have wanted presidential clemency in the first place -- even though historians say it was likely available to her during her own lifetime -- both because it would have admitted guilt and because she wore her conviction with pride.

"She absolutely would not have wanted the pardon," said Deborah Hughes, the president and CEO of the National Susan B. Anthony Museum and House in Rochester, New York, where on Tuesday the news of Trump's pardon was met with surprise.

"Absolutely not," said Ann Gordon, a former Rutgers University professor who edited an extensive collection, "The Selected Papers of Elizabeth Cady Stanton and Susan B. Anthony." "When you're asking for a pardon, you're saying, I did something wrong."

Issued on the centennial of the 19th Amendment, which gave women the right to vote, Trump's pardon appeared designed to commemorate an American icon whose work helped transform American society. He first teased the pardon to reporters aboard Air Force One on Monday, saying it would be directed at someone "very, very important." In a morning event marking the 19th Amendment anniversary, Trump revealed the pick and noted Anthony's history.

"She was guilty for voting," he said. "And we are going to be signing a full and complete pardon."

Later, Trump appeared to acknowledge that Anthony may not have wanted a pardon -- but said he had gone ahead and granted one anyway.