Michelle Obama gave a speech that earned laughter and applause
Hillary Clinton's name was met with boos and jeers from a restless crowd at the opening night of the Democratic National Convention, despite calls from Bernie Sanders for unity.
Some of the speakers in Philadelphia appeared exasperated as their speeches in support of Mrs Clinton were met with chants of "Bernie, Bernie" from vocal demonstrators.
It culminated in comedian Sarah Silverman - a one-time supporter of the Vermont senator - turning to the booing Sanders fans and telling them: "You're being ridiculous."
But the crowd grew calmer for First Lady Michelle Obama as she gave a rousing speech that earned laughter and applause from former President Bill Clinton in the auditorium.
Mrs Obama drew regular comparisons between Mrs Clinton and Republican nominee Donald Trump - without mentioning the billionaire businessman by name.
She said the US needed a president who knew issues could not "be boiled down to 140 characters" and urged voters not to believe anyone who said they could make America great again - because it was still "the greatest country on earth".
Mrs Obama also praised Mrs Clinton for advancing the cause for women with her nomination so "all our sons and daughters can now take for granted that a woman can be president".
Newstalk.com's Shona Murray has been speaking to delegates at the convention in Philadelphia.
Mr Sanders took to the stage and told those holding aloft "Bernie" signs to unite behind Mrs Clinton ahead of November's election.
"Hillary Clinton will make an outstanding president and I am proud to stand with her here tonight," he said.
The senator said he had known Mrs Clinton for 25 years and had watched her fight for children's rights and universal healthcare.
He launched the party's convention by urging delegates to unite against the Republican candidate.
Meanwhile, Mr Sanders acknowledged the disappointment in the conventional hall that he had missed out on the Democratic nomination, telling the crowds: "I think it's fair to say that no one is more disappointed than I am."
The senator's impassioned speech in support of his one-time rival came despite deep anger among Democratic supporters at embarrassing leaked e-mails which suggest party insiders tried to prevent him from winning the nomination.
Officials from the Democratic National Committee have apologised for the "inexcusable" remarks found within the messages, which have prompted the chairwoman to step down.
In another attempt to achieve unity ahead of Mrs Clinton formally accepting the nomination on Thursday, Mr Sanders said that the US is stronger when "black and white, Latino, Asian-American, Native American - when all of us stand together".
Outside the convention hall more than 50 protesters were detained while showing their anger at Mrs Clinton's nomination.