Joe Biden has become the first sitting US president to visit the site of the Tulsa massacre – 100 years since one of America’s darkest episodes of racial violence.
Hundreds of black people were killed by a white mob in the city’s Greenwood district between 31 May and 1 June 1921.
Mr Biden led a moment of silence for the victims of the mass killing, alongside three survivors.
Viola Fletcher, Hughes Van Ellis and Lessie Benningfield Randle were all present a century ago when the killings happened in Oklahoma.
Mr Biden said: “For much too long the history of what took place here was told in silence.
“My fellow Americans, this was not a riot. This was a massacre, and among the worst in our history. But not the only one.”
He added: “Some injustices are so heinous, so horrific, so grievous, they cannot be buried, no matter how hard people try.
“Only with truth can come healing.”
Latasha Sanders, 33, waited outside with her five children and her nephew to try and see the president.
She said: “It’s been 100 years, and this is the first we’ve heard from any US president.
“I brought my kids here today just so they could be a part of history and not just hear about it, and so they can teach generations to come.”
Last year, President Donald Trump planned a political rally in Tulsa on 19 June – a date known as “Juneteenth” – which is marked as the day slavery ended in the US in 1865.
In the end, the Republican’s event was delayed for a day due to criticism.
Public awareness over what happened in Greenwood has grown in recent years, as the incident was not taught in schools or reported in local newspapers.
White residents shot and killed as many as 300 black people and burned and looted businesses and homes.
It came after a white woman accused a black man of assault, a charge which was never proven.
Insurers refused to pay out for the damage from the riots and no one was prosecuted for the violence.
During his speech, Mr Biden spoke of how he wanted to improve life for black Americans.
This included promises to spend more money supporting minority-owned businesses, as well as making sure voting rights were protected.
He raised concerns over the state of the democratic process in the country following the 6 January riots in Washington DC, and Mr Trump’s unfounded complaints over last year’s election results.
Mr Biden said he was told by one of the Tulsa survivors that the events of 6 January “reminded her of what happened here in Greenwood 100 years ago”.
He added that intelligence agencies had reported that terrorism from white supremacy was currently the “most lethal threat” to America.
The president added that he wanted to do more to help people vote, but he was restricted by slim majorities in both houses of Congress.