CHICAGO - One month after replacing President Biden atop the Democrats' 2024 ticket, Vice President Kamala Harris accepted her party's presidential nomination as she delivered the most important speech of her political career.

In a roughly 40 minute speech that was the crowning and concluding moment of the four-day Democratic National Convention in Chicago's United Center, the vice president promised to chart "a new way forward" if Americans elect her to succeed her boss - President Biden.

And Harris warned Americans against returning former President Trump, the Republican nominee, to power. 

"In many ways, Donald Trump is an unserious man," the vice president argued. "But the consequences of putting Donald Trump back in the White House are extremely serious."

CLICK HERE FOR FOX NEWS UPDATES FROM THE DEMOCRATIC CONVENTION

Kamala Harris takes the stage on Day 4 of the Democratic National Convention

Democratic presidential nominee and U.S. Vice President Kamala Harris takes the stage on Day 4 of the Democratic National Convention (DNC) at the United Center in Chicago, Illinois, U.S., August 22, 2024.  (REUTERS/Brendan Mcdermid)

And Harris cast herself as someone who could bring a deeply polarized nation together, saying "with this election, our nation has a precious, fleeting opportunity to move past the bitterness, cynicism, and divisive battles of the past."

"I will be a president who unites us around our highest aspirations," she pledged. "A president who leads — and listens. Who is realistic. Practical. And has common sense. And always fights for the American people."

Harris noted that "there are people of various political views watching tonight. And I want you to know: I promise to be a president for all Americans."

WATCH: TRUMP JOINS FOX NEWS FOLLOWING HARRIS ADDRESS 

Pointing to her years as a prosecutor, San Francisco district attorney and California attorney general before winning election to the U.S. Senate and four years ago as the nation's vice president, she said "from the courthouse to the White House, that has been my life’s work."

Harris made history in 2020 as the first woman elected vice president. And she made the record books again this month as the first Black woman and first person of South Asian descent to win a major party's presidential nomination. And if she wins in November, Harris could become the nation's first female president.

Harris has been riding a wave of energy and enthusiasm – both in polling and in fundraising – since replacing President Biden at the top of the Democrats' 2024 ticket four weeks ago.

And she walked out on to the stage at Chicago's United Center arena to thunderous applause and a sustained standing ovation that included chants of "yes, you can." 

TRUMP TAKES AIM AT HARRIS AS SHE DELIVERS HER CONVENTION ADDRESS 

After describing herself as the daughter of an Indian scientist who immigrated to America "with an unshakable dream to be the scientist who would cure breast cancer," she recounted how the sexual abuse of a childhood friend fueled her desire to become a prosecutor. 

"Like the people I grew up with, people who work hard, chase their dreams, and look out for one another, on behalf of everyone whose story could only be written in the greatest nation on earth, I accept your nomination to be President of the United States of America," Harris said. 

Trump repeatedly took to social media throughout the vice president's address to take aim at his 2024 rival. 

Trump appears in Asheboro, North Carolina

Former President Trump, the Republican presidential nominee, gestures during a campaign rally at the North Carolina Aviation Museum & Hall of Fame in Asheboro, North Carolina, August 21, 2024. (Photo by PETER ZAY/AFP via Getty Images)

As Harris talked about her early years, Trump wrote on his Truth Social platform, "A lot of talk about childhood, we’ve got to get to the Border, Inflation, and Crime!"

Minutes later, as Harris in her speech pledged that building the middle class "will be a defining goal of my presidency, Trump pointed toward her three and a half years as the nation's vice president during the Biden administration and asked, "Why didn’t she do something about the things of which she complains?"

Harris, as expected, spent a portion of her address spotlighting reproductive rights, an issue that has energized and mobilized Democrats in the two years since the blockbuster ruling by the Supreme Court's conservative majority to overturn the landmark Roe v. Wade ruling, which had legalized abortion nationwide.

She argued that "Donald Trump hand-picked members of the United States Supreme Court to take away reproductive freedom."

And she vowed that "when Congress passes a bill to restore reproductive freedom, as President of the United States, I will proudly sign it into law."

But she also touched on border security, an issue that Trump and fellow Republicans have hammered the Biden administration over the surge of migrants into the country in the past three and a half years.

Vice President Kamala Harris, following her nomination acceptance speech at the Democratic National Convention, is joined on stage by her running mate, Minnesota Gov. Tim Walz, and their spouses, Second Gentleman Doug Emhoff and Minnesota First Lady Gwen Walz, in Chicago, Illinois on Aug. 22, 2024.

Vice President Kamala Harris, following her nomination acceptance speech at the Democratic National Convention, is joined on stage by her running mate, Minnesota Gov. Tim Walz, and their spouses, Second Gentleman Doug Emhoff and Minnesota First Lady Gwen Walz, in Chicago, Illinois on Aug. 22, 2024. (Fox News - Paul Steinhauser)

Harris pointed to a border security bill with some bipartisan support that was making its way through Congress earlier this year before Republicans turned against the measure after prompting from Trump.

"As President, I will bring back the bipartisan border security bill that he killed.  And I will sign it into law," Harris reiterated.

Harris also pledged that "as Commander-in-Chief, I will ensure America always has the strongest, most lethal fighting force in the world. I will fulfill our sacred obligation to care for our troops and their families. And I will always honor, and never disparage, their service and their sacrifice."

The comments spurred chants of "USA, USA" from the crowd of Democratic politicians, officials, activists, and supporters in the arena.

Taking aim at Trump, Harris said "I will not cozy up to tyrants and dictators like Kim-Jong-Un, who are rooting for Trump."

She pledged that if elected, she would continue the Biden administration's efforts in ending two major international conflicts.

"I will stand strong with Ukraine and our NATO allies," she said as she pointed to the eastern European nation's ongoing war against Russian aggression.

And pointing to the Middle East, she emphasized, "Let me be clear: I will always stand up for Israel’s right to defend itself and I will always ensure Israel has the ability to defend itself. Because the people of Israel must never again face the horror that the terrorist organization called Hamas caused on October 7th."

But she added that "at the same time, what has happened in Gaza over the past 10 months is devastating. So many innocent lives lost. Desperate, hungry people fleeing for safety, over and over again. The scale of suffering is heartbreaking."

Pro-Palestinian demonstrators have been protesting outside the Democrats' convention the entire week, as the party remains partially divided over the Biden administration's support for Israel in its war with Hamas in Gaza.

"President Biden and I are working to end this war such that Israel is secure, the hostages are released, the suffering in Gaza ends, and the Palestinian people can realize their right to dignity. Security. Freedom. And self-determination," in a line that elicited loud cheers.

Biden ended his re-election bid on July 21, after his disastrous late June performance in a debate with Trump fueled questions over whether the 81-year-old president was physically and mentally able to handle another four years in the White House - and sparked calls from within the Democratic Party for him to drop out of the race.

Biden and Harris on DNC stage

Democratic presidential nominee Vice President Kamala Harris, left, clasps her hand in the air with President Joe Biden at the Democratic National Convention, Monday, Aug. 19, 2024, in Chicago. (AP Photo/Jacquelyn Martin) (AP Photo/Jacquelyn Martin)

Biden, in a well regarded and emotional address, spoke on the first night of the convention before heading to California for a brief vacation.

Harris, near the top of her speech, praised her boss.

"To our president, Joe Biden. When I think about the path that we have traveled together, Joe, I am filled with gratitude," she said. "Your record is extraordinary, as history will show, and your character is inspiring."

CLICK HERE TO GET THE FOX NEWS APP

Harris also gave a shutout to her running mate, Minnesota Gov. Tim Walz, who addressed the convention the previous night.

"To Coach Tim Walz. You are going to be an incredible vice president," she said.

Since Harris took over for Biden atop the Democrats' ticket, the former president has tried to paint her as a far-left extremist.

Trump, in an interview with Fox News anchors Bret Baier and Martha McCallum following the vice president's speech, charged that Harris is "a Marxist. She always was. She always will be."

The former president described Harris' speech as "a lot of complaining."

"She didn't talk about China. She didn't talk about fracking. She didn't talk about crime. She didn't talk about 70% of our people living in poverty. She didn't talk about housing," he emphasized. "She presided over the weakest border in the history of our country."

Get the latest updates from the 2024 campaign trail, exclusive interviews and more at our Fox News Digital election hub.