The United States on Thursday designated Juneteenth, which marks the end of slavery in the country, a federal holiday with President Joe Biden urging Americans "to learn from our history."

Most US states recognize Juneteenth and commemorate the day, but the bill made June 19 the 12th federal holiday -- and the first new one in 38 years.

The date has taken on renewed resonance in recent years with millions of Americans confronting the country's living legacy of racial injustice.

"This is a day of profound weight and profound power, and to remember the moral stain and the terrible toll that slavery took on the country, and continues to take -- what I've long called America's original sin," Biden said before signing the bill into law.

He hailed the country's "extraordinary capacity to heal and to hope and to emerge from those painful moments and a bitter, bitter version of ourselves."

US Vice President Kamala Harris and Opal Lee (2nd L), the activist known as the grandmother of Juneteenth, watch as US President Joe Biden holds the signed Juneteenth National Independence Day Act, in the East Room of the White House
US Vice President Kamala Harris and Opal Lee (2nd L), the activist known as the grandmother of Juneteenth, watch as US President Joe Biden holds the signed Juneteenth National Independence Day Act, in the East Room of the White House AFP / Jim WATSON

The bipartisan measure cleared the Senate by unanimous consent on Tuesday after one Republican in the chamber ended his objection, and the House of Representatives passed it in a 415-14 vote on Wednesday.

"All Americans can feel the power of this day and learn from our history and celebrate progress and grapple with the distance we've come, but (also) the distance that we have to travel," Biden told activists and politicians gathered at the White House.

Among those present was leading campaigner Opal Lee, 94, known as the "grandmother of Juneteenth." Vice President Kamala Harris held her hand as Biden signed the act and presented her with a commemorative pen.

Juneteenth National Independence Day is held on June 19 to celebrate the day in 1865 when the last enslaved African Americans learned that they were free.

Black Lives Matter protesters in New York on the anniversary of the death of George Floyd, who was murdered by a white officer
Black Lives Matter protesters in New York on the anniversary of the death of George Floyd, who was murdered by a white officer AFP / Ed JONES

A Union Army general in Galveston, Texas -- where president Abraham Lincoln's Emancipation Proclamation of 1862 had yet to be enforced nearly three years later -- announced that slavery was abolished in Texas and across the country.

June 19 falls on a Saturday this year, and will be largely marked on Friday. It is the first new federal holiday in the United States since Martin Luther King Jr. Day was created in 1983.

Juneteenth last year came against a backdrop of protests fueled by the death of George Floyd, a 46-year-old Black man killed by a white police officer in Minneapolis, Minnesota.

The horrifying killing, which was captured on phone video as the officer knelt on Floyd's neck for more than nine minutes, kicked off the biggest civil rights protests in the United States since the 1960s.

The officer has since been convicted of murder and is awaiting sentencing.

Major US companies including Nike and Twitter announced in 2020 they were making Juneteenth a paid holiday for employees, and many other companies have since followed suit.

Vice President Kamala Harris, the first person of mixed race and the first woman to hold the office, recalled that the White House was built by slaves and said "we must teach our children our history, because it is part of our history as a nation."

"Today is a day of celebration, and it's also a day of pride," she said.

Democrats and Republicans have struggled to unite on legislative issues in recent years, with political divisions impacted by debates over race, immigration and other social issues, but Juneteenth was a rare exception.

Last year, then-president Donald Trump was forced to re-schedule a rally on Juneteenth in Tulsa, Oklahoma, a city known for one of the deadliest-ever massacres of African Americans.

He then claimed credit for raising awareness about the day -- which was little known among many non-Black Americans -- saying "I did something good: I made Juneteenth very famous."

The day is usually celebrated with parades, concerts or neighborhood parties.