The Rev. Jesse Jackson, the civil rights leader and 1988 Democratic presidential candidate, received a standing ovation when he was wheeled on stage, right after a video on the civil rights movement ended.

Jackson was joined by other civil rights icons, including the Rev. Al Sharpton.

Penny Flanagan, Minnesota's lieutenant governor, introduced Rep. Maxine Waters to speak at the DNC. Waters received a standing ovation before speaking.

Flanagan is poised to serve as Minnesota's next governor if Gov. Tim Walz steps down to serve as vice president.

As a citizen of the White Earth Band of Ojibwe, Flanagan would be the first Native American female governor.

DNC Chair Jamie Harrison took the stage to tout the Democrats' work over the last four years and the goals of a Harris-Walz administration.

"The fight continues, and there is still more work to do," he said.

"I know that when we elect Kamala Harris and Tim Walz, they will build on our accomplishments and they will create a country that works for every American," he added.

Harrison encouraged voters to be active in the coming weeks for all races down the ticket.

"In my beloved home state of South Carolina, our motto is, 'While I breathe, I hope.' Folks, I believe in the power of hope, but it's going to take more than hope to win this election," he said.

Delegates and other attendees here in the United Center are amped up -- and have been paying attention.

Chicago Mayor Brandon Johnson got a rousing applause when he said his daughter will be able to see herself in Harris. And when Democratic National Committee Chair Jamie Harrison started off with one of Harris' marquee remarks, the crowd quickly finished it with him.

"When we fight…" Harrison said.

"We win!" the crowd erupted.

-ABC News' Tal Axelrod