DNC 2020: Joe Biden accepts Democratic presidential nomination to challenge Trump

Joe Biden vowed to unite an America torn by crisis and contempt Thursday night as he accepted the Democratic presidential nomination.

Biden addressed his fellow Democrats and millions of Americans at home who he hopes will send him to the White House to replace Trump - though his triumphant moment was drained of immediate drama by the coronavirus pandemic, which left him speaking to a nearly empty arena rather than a joyously cheering crowd.

The night's keynote address was the speech of a lifetime for Biden, who would be the oldest president ever elected if he defeats Trump in November.

Biden's Democratic Party has sought this week to put forward a cohesive vision of values and policy priorities, highlighting efforts to combat climate change, tighten gun laws and embrace a humane immigration policy.

Biden's positive focus Thursday night marked a break from the dire warnings offered by former President Obama and others the night before.

Democratic presidential candidate and former Vice President Joe Biden, his wife Jill Biden and U.S. Senator and Democratic candidate for Vice President Kamala Harris celebrate outside the Chase Center after Joe Biden accepted the 2020 Democratic presidential nomination.

Fireworks lit the sky outside as the convention ended, giving a celebratory feel at last to the affair.

Jill Biden (L) and husband former vice-president and Democratic presidential nominee Joe Biden wear facemasks as they watch fireworks outside the Chase Center in Wilmington, Delaware.

Joe Biden and U.S. Senator and Democratic candidate for Vice President Kamala Harris celebrate after Joe Biden accepted the 2020 Democratic presidential nomination.

Biden's call for unity comes as some strategists worry that Democrats cannot retake the White House simply by tearing Trump down" Biden needs to give his sprawling coalition something to vote for.

Though he has been in the public spotlight for decades, much of the electorate knows little about Biden's background before he began serving as President Barack Obama's vice president in 2008.

A supporter watches Democratic presidential candidate former Vice President Joe Bidens acceptance speech from a parking lot outside Chase Center during the Democratic National Convention.