On Thursday, President Joe Biden signed a bill into law commemorating June 19, which marks the true end of slavery in the U.S., as a federal holiday.

"This is a day of profound weight and profound power," Biden said at the signing ceremony, calling it a day to remember "the moral stain" of slavery. As he signed the bill, Opal Lee, who's 94 and has led a decade-long effort to make Juneteenth a holiday, stood by his side on stage. The Texas native was one of the first to get a pen Biden used to sign the legislation.

Vice President Kamala Harris also highlighted the significance of establishing the holiday.

"National holidays are something important. These are days when we as a nation have decided to take stock and often to acknowledge our history," Harris said. "We must learn from our history, and we must teach our children our history."

"We have come far and we have far to go, but today is a day of celebration," she said.

On June 19, 1865, Union troops arrived in Galveston, Texas to tell the state's enslaved people they were free. This came more than two months after the end of the Civil War, and years after President Abraham Lincoln issued the Emancipation Proclamation (which freed enslaved people on paper, but not right away in practice).

Advocates have been calling for a federal holiday for years, but the turning point in their fight came after last summer's protests against police brutality and racial injustice following the murder of George Floyd.

While designating Juneteenth as a holiday raises awareness of an important historical moment, Bernice King, CEO of The King Center, a social change nonprofit, and Martin Luther King Jr.'s daughter, said Congress needs to do more than take ceremonial action. She called on lawmakers to pass legislation to prevent police violence and voter suppression.

"There is just so much that has to happen in our Senate to really deliver substance to Black people," she said on CNN before the signing.

Read the full article about Juneteenth by Siobhan Neela-Stock at Mashable.