Former US vice president Joe Biden has secured enough delegates in the Democratic nominating contest to clinch the party's presidential nomination, according to Edison Media Research.
The milestone is largely symbolic, since all other major candidates stopped campaigning in April.
"It was an honour to compete alongside one of the most talented groups of candidates the Democratic party has ever fielded," Mr Biden said in a statement issued last Friday, when his campaign determined that he had crossed the delegate threshold.
"I am proud to say that we are going into this general election a united party."
Mr Biden launched his run in such a large field that, for much of last year, many thought no candidate would win the nomination outright, setting up a possibly contested convention.
Instead, Mr Biden became the presumptive nominee much earlier in the calendar than other recent Democratic candidates, providing him extra months to retool his campaign for the general election.
But Mr Biden also faces challenges no other nominee has had, including a series of cascading crises that have transformed the political landscape.
The coronavirus pandemic shut down the country for months, causing an economic crisis with jobless numbers in the double digits.
And now the killing of George Floyd, an unarmed black man who died after Minneapolis police officers pinned him to the ground, has caused a wave of massive demonstrations in cities and towns across the country.
In response, Mr Biden has shifted his message from restoring norms shattered by President Donald Trump to a broader call for societal and government change.
"We aren't just building the movement that will defeat Donald Trump, we are building the movement that will transform our nation," Mr Biden added in his statement.
When Mr Biden entered the presidential race last year, he joined a historically large and diverse field of competitors.
Though he led in national polls for much of the campaign, Mr Biden's candidacy stalled in early states.
He finished fourth in Iowa, behind Pete Buttigieg, Bernie Sanders and Elizabeth Warren.
Then he dropped to fifth in New Hampshire with Amy Klobuchar joining the group of candidates with better finishes. No Democratic candidate had ever gone on to become the nominee after finishing below second in the 'Granite State'.
Mr Biden began rebounding in the next contest, finishing second in Nevada.
Then he clobbered the field in South Carolina, largely due to support from black voters, many of whom saw him as the strongest candidate to defeat Mr Trump.
Moderate candidates quickly lined up behind Mr Biden, letting him plough through the next set of states.
By April, Mr Biden's top competitors had all endorsed his candidacy, including Mr Sanders, who officially endorsed him in April with a joint video.
Wooing Mr Sanders's intensely loyal followers remains a priority for Mr Biden. He's convened six policy panels that include Mr Sanders's most influential backers, like Alexandria Ocasio-Cortez.
Mr Biden also pledged to name a female running mate, an appeal to female voters who make up the majority of the Democratic electorate.
"I am going to spend every day between now and November 3 fighting to earn the votes of Americans all across this great country so that, together, we can win the battle for the soul of this nation, and make sure that as we rebuild our economy, everyone comes along," Mr Biden said. (© Washington Post)