Joe Biden has become the first sitting president to commemorate the 1921 Tulsa Massacre – one of the worst incidents of racial violence in US history.
Mr Biden flew to Tulsa, Oklahoma, on Tuesday to mark the 100th anniversary of the attack, which claimed some 300 African-American lives.
The two days of violence, sparked by a white mob, were largely erased from history for decades.
It re-entered the national discourse amid racial justice protests last year.
On 31 May 1921, a group of white Americans sacked the affluent and predominantly black neighbourhood of Greenwood in Tulsa.
The community – known by the moniker of “Black Wall Street” – was the country’s wealthiest African-American neighbourhood until its many homes and businesses were burned down in the riot.