Kamala Harris is poised to make history as the first black woman to accept a spot on a major party's presidential ticket, a moment intended to galvanise Democratic voters heading into the campaign against President Donald Trump.
This will be her second time speaking to the Democratic National Convention.
But the stakes are higher than ever before as Harris tries to unite the party behind Joe Biden while also introducing herself to a broader US audience that may be tuning into the campaign for the first time.
"For somebody with her wealth of background and experience, she's still fresh. She's still new," said Ohio Representative Marcia Fudge, a former chairwoman of the Congressional Black Caucus who endorsed Ms Harris' 2020 presidential primary run before throwing her support behind Mr Biden in March.
"I think people are looking for that."
Former president Barack Obama will speak before Ms Harris on Wednesday, the country's first black president handing off to the first black woman on a major presidential ticket.
Barack Obama with his then-running mate Joe Biden at the Democratic National Convention in 2008. Source: Sacramento Bee/TNS/Sipa USA
He is due to unleash a scathing attack on Mr Trump, accusing him of abusing power to help himself and his cohorts while failing at his job.
Mr Obama will say US democracy is "at stake right now" and plans to slam Mr Trump over the country's coronavirus pandemic response and job losses, according to remarks released by convention organisers.
"He's shown no interest in putting in the work, no interest in finding common ground, no interest in using the awesome power of his office to help anyone but himself and his friends," Mr Obama will say.
Ms Harris will be introduced by her sister Maya and her niece Meena as well as Ella Emhoff, her stepdaughter.
The senator's advisers say Ms Harris will tell her story while highlighting the examples and experiences of others.
Ms Harris also plans to describe a country where everyone is welcome and entitled to equal opportunity and legal protection, and make the case that Mr Biden is uniquely qualified to lead the country, aides say.
In a virtual address on Wednesday to the convention's Asian American and Pacific Islander Caucus, Ms Harris - the daughter of Jamaican and Indian immigrants - said she would deliver her speech "knowing that I stand on the shoulders of so many people who are on this call and those who came before us".
