Ahead of Harris herself, who will become the first Black woman and first person of Indian descent to be nominated for national office by a major political party, the night featured leading, history-making women in politics.
Former Rep. Gabby Giffords, D-Ariz., struck a chord early in the event, in an opening segment focusing on gun control.
"I've known the darkest of days, days of pain and uncertain recovery," said Giffords, who has become a leading voice in ending gun violence after surviving a gunshot wound to the head. "But confronted by despair, I've summoned hope. Confronted by paralysis and aphasia, I've responded with grit and determination. I put one foot in front of the other. I found one word and then I found another. My recovery is a daily fight, but fighting makes me stronger. Words once came easily; today I struggle with speech. But I have not lost my voice."
"America needs all of us to speak out, even when you have to fight to find the words," she continued.
Reacting on Twitter, viewers called Giffords' speech powerful and inspiring, and said her French horn playing in the segment was impressive.
Former Secretary of State Hillary Clinton spoke of "breaking down barriers."
"Tonight, I'm thinking of the girls and boys who see themselves in America's future because of Kamala Harris, a Black woman, the daughter of Jamaican and Indian immigrants, and our nominee for vice president," said Clinton, the first female nominee of a major U.S. political party.
Her most memorable line, though, referenced her 2016 run against President Donald Trump, as she urged people to vote. "And don't forget, Joe and Kamala can win by 3 million votes and still lose. Take it from me," she said.
House Speaker Nancy Pelosi, the first woman to lead a party in Congress, said that "we are unleashing the full power of women to take their rightful place in every part of our national life." Harris and Biden, she said, would champion policies impacting women, including defending a woman's right to choose and securing a guarantee for child care.
"Kamala Harris is the vice president we need right now, committed to our constitution, brilliant in defending it and a witness to the women of this nation that our voices will be heard," Pelosi said.
"Tonight we've heard from the people who make America work, people who put their lives on the line to keep our country going, and since COVID-19 hit, they've taken one gut punch after another," said Warren, the first woman elected to the Senate from Massachusetts. "And now, parents are stuck -- no idea when schools can safely reopen and even fewer childcare options. The devastation is enormous."
Her appearance sparked conversations on Twitter on what role she could take in a potential Biden-Harris White House.
Other female speakers ahead of Harris' appearance included New Mexico Gov. Michelle Lujan Grisham, the first Democratic Latina to be elected governor. Addressing climate change, Grisham said she is proud that her state has "shown what climate leadership looks like."