President Joe Biden signed legislation creating a new federal holiday honoring the abolition of slavery on Thursday, saying it would go down as one of the finest honors he has had as president.

“We have come far, and we have far to go. But today is a day of celebration,” said Vice President Kamala Harris, who spoke before the president at the White House signing ceremony.

“Great nations don’t ignore their most painful moments,” Biden told the East Room audience of dozens of lawmakers, activists, and community leaders. “They embrace them.”

“In short, this day doesn’t just celebrate the past. It calls for action today.”

“Today is a day of celebration,” said Harris, the country’s first African-American vice president. “It is not only a day of pride, it is also a day for us to reaffirm and rededicate ourselves to action.”

Juneteenth marks the day when the last enslaved Black Americans discovered they were free after the American Civil War between Confederate slave-holding states in the south and Union free states in the north.

On June 19, 1865, Union troops delivered the word of freedom to enslaved Black people in Galveston, Texas, two months after the Confederacy surrendered.

President Abraham Lincoln had signed the Emancipation Proclamation two and a half years earlier, liberating American slaves in 1863.

Juneteenth National Independence Day will be the 12th legal public holiday, counting Inauguration Day, and the first new one since Martin Luther King Jr. Day was signed into law by then-President Ronald Reagan in 1983.

Because June 19 comes on a Saturday this year, the Office of Personnel Management, the federal government’s human resources office, announced Thursday that most federal workers would celebrate the new holiday — Juneteenth National Independence Day — on Friday.

According to the exchange, the New York Stock Exchange will not shut for Juneteenth this year, but may consider suspending markets for the holiday in 2022.

In a tweet, US presidential historian Michael Beschloss praised Biden’s signing of the bill, sayinh, “Juneteenth should have become a federal holiday long ago.”

The holiday legislation was approved by both houses of Congress with overwhelming support. The law was unanimously adopted by the Senate Tuesday night, and it was passed by the House 415-14.

Biden emphasized the bill’s strong support from legislators of both parties. He ran for president on a platform of uniting the nation and working with Republicans, but his first big measure to give more COVID relief to American consumers and companies was approved along party lines, and he has failed to rally legislators behind a large public works package.

“I hope this is the beginning of a change in the way we deal with one another,” Biden said.

At the signing ceremony, Biden got down on one knee and embraced Opal Lee, a 94-year-old Texan who has spent her whole life advocating for Juneteenth to be declared a national holiday.

“You just received a very special recognition from the president of the United States,” Harris quipped, eliciting laughter from the luminaries gathered at the White House for the bill signing.