ATLANTA (REUTERS) - Thousands marched in US cities, major companies gave employees the day off and people in coronavirus lockdown held online forums on Friday (June 19) as America marked Juneteenth, a holiday commemorating the end of Black slavery that carries special resonance this year.

After a wave of recent protests and national soul-searching about the country's legacy of racial injustice, marchers took to the streets from Atlanta to Oakland to mark the day and protest police brutality.

With many formal Juneteenth events cancelled due to coronavirus concerns, activists instead organized street marches and "car caravans" to give people a way to show solidarity.

The annual Juneteenth celebration of the emancipation of slaves a century and a half ago comes this year on the heels of mass protests triggered by the killing of George Floyd, a Black man who died after a white Minneapolis police officer pinned him to the ground with a knee to his neck for nearly nine minutes.

Four Democratic US senators are to introduce a bill to declare Juneteenth as a federal holiday.

"Juneteenth is the oldest celebration of the end of slavery in the US. And it should be recognised as a federal holiday," Tina Smith, one of the senators, wrote on Twitter.

Weeks of mounting demands to end police brutality and racial injustice animated rallies expected in cities coast to coast, including Washington, Philadelphia, Chicago and Los Angeles.

In Atlanta, an important center of the civil rights movement of the 1960s, about 1,000 people gathered at Centennial Olympic Park downtown for a peaceful march on the state capitol building.

Emotions were running high in Atlanta after Rayshard Brooks, an African American, was fatally shot in the back by a white policeman in the parking lot of a fast-food restaurant in the city. The policeman was terminated by the department and charged with murder.

Many Atlanta marchers carried signs proclaiming "Black Lives Matter," or "Get your knee off our necks," and "I can't breathe," referring to Floyd's death.

Marcher Antonio Jeremiah Parks, 27, of Atlanta said the civil rights movement had not yet fulfilled its promises.

"Civil rights isn't over," said Parks, who is Black and works at a homeless shelter. "We still feel the pain of slavery. It's not healed, and won't be until we're treated the same."

Leia Shanks, 34, who is white and works in retail, said: "We're here in solidarity," she said. "We need to stand against racism and even though it's 2020, what's happening now isn't right."

Major US companies have declared June 19 a paid holiday this year, some for the first time. Ride-hailing service Uber declared Friday a paid day off and several banks such as JPMorgan Chase & Co and Capital One Financial Corp closed offices or branches early.

In New York City, a few hundred protesters mostly wearing masks due to the coronavirus, gathered outside the Brooklyn Museum.

Maxwell Awosanya was handing out free snacks and water to the swelling crowd of protesters outside the museum.

"African-American history is American history. Black history is American history. We need to be heard, we need people to see us. ... we need to be understood, we need to be seen as equal," he said.

A diverse crowd, including parents with children in strollers and a large contingent of people on bicycles, marched in downtown Brooklyn, chanting "No justice, no peace" and "Say his name, George Floyd."

In Texas, where Juneteenth originated, Lucy Bremond oversees what is believed to be the oldest public celebration of the occasion each year in Houston's Emancipation Park. This year a gathering that typically draws some 6,000 people to the park will be replaced with a virtual observance.

"There are a lot of people who did not even know Juneteenth existed until these past few weeks," Bremond said.

ABOLITION OF SLAVERY

Juneteenth, a blend of June and 19th, commemorates the US abolition of slavery under President Abraham Lincoln's 1863 Emancipation Proclamation, belatedly announced by a Union army in Galveston, Texas, on June 19, 1865, after the Civil War ended.

Texas officially made it a holiday in 1980, and 45 more states and the District of Columbia have since followed suit.

On the West Coast, union dockworkers at nearly 30 ports planned to mark the occasion by staging a one-day strike.

Some 1,500 protesters gathered at the Port of Oakland to join local dockworker unions in the port shutdown. The gathering was due to march to downtown Oakland, with many of the dock workers driving in a caravan along the way.

But much of the focus of the annual observance was taking take place on social media, with online lectures, discussion groups and virtual breakfasts, to guard against coronavirus.

"We have been training our staff on how to use technology to present their events virtually and online," said Steve Williams, president of the National Juneteenth Observance Foundation.

Many chapters planned "car caravans": slow-speed processions of motorists honking horns and waving their arms as they wend their way through neighbourhoods, Williams said.

A focal point of Juneteenth observances this year is likely to be Tulsa. President Donald Trump is travelling to the Oklahoma city for his first campaign rally in three months, originally scheduled for Friday but moved to Saturday after an outcry.

Tulsa was the scene of a notorious massacre of African Americans by white mobs in 1921.