Kamala Harris, Tim Walz make first appearance as running mates during rally at Temple University

PHILADELPHIA (WPVI) -- Vice President Kamala Harris and her newly announced presidential running mate, Minnesota Gov. Tim Walz, made their first campaign appearance together on Tuesday evening before a large crowd in Philadelphia.

Hundreds of supporters waited in lines outside the Liacouras Center at Temple University, which has a capacity of 10,000 people, for the event, and packed the arena.

That crowd gave Walz and Harris a long-standing ovation as they took the stage to the song "Freedom" by Beyoncé.

Walz and Harris hit the stage and touted an agenda of unifying the country and working for all Americans. They also shared their vision in comparison to the conservative policies that are being pushed by former President Donald Trump and his running mate, Sen. JD Vance.

"We need to level set; we are the underdogs in this race, but we have the momentum, and I know exactly what we are up against," she said.

Harris said her campaign is not just a fight against Trump but a "fight for the future."

RELATED: Who is Tim Walz, the Minnesota governor selected as Harris' running mate?

Walz touted Harris' experience as a prosecutor, senator, and vice president during his speech.

"She took on predators and fraudsters, took down transnational gangs, stood up against powerful corporate interests, she's never hesitated to reach across the aisle if it meant improving people's lives. And -- she brings joy to everything she does," Walz said.

FULL VIDEO | Kamala Harris, Tim Walz speak during rally at Temple University

Kamala Harris, Tim Walz make first appearance as running mates during Philadelphia rally

The governor also spoke about his history from his days as a teacher to legislating as an elected official.

"It was my students. They encouraged me to run for office. They saw in me what I was hoping to instill in them - a commitment of common good, a belief that one person can make a difference," he said.

"These same values I learned on the family farm and tried to instill in my students, I took to Congress and the state capital, and now, Vice President Harris and I are running to take them to the White House," he added.

Walz took several shots at Trump, contending the former president's policies while in office hurt Americans.

"He drove our economy into the ground. And make no mistake, violent crime was up under Donald Trump. That's not even counting the crimes he committed," he said.

RELATED: JD Vance makes first stop in Philadelphia as Donald Trump's running mate

Pennsylvania Gov. Josh Shapiro, who was in the running for the vice presidential spot on the ticket, received a huge ovation from the crowd as he took the stage before Walz and Harris spoke.

"I want you to know I am going to continue to pour my heart and soul into serving you as your governor," he said.

He also touted Harris' record, contending she is "battle-tested and ready to go."

Shapiro went on to criticize former President Donald Trump for his role in dismantling reproductive rights and warned that if the former president is re-elected more restrictions could come.

"Let me tell you something, I am not going back," he said to the crowd.

Shapiro also lauded Walz, calling him a "great patriot" and "dear friend."

"I think it is fitting and I think it is special for Kamala Harris and Tim Walz to launch their campaign here in Philly, the City of Brotherly Love, and importantly they chose to launch their campaign right here in the birthplace of real freedom," he said.

Walz, during his speech, praised Shapiro as a "visionary leader" and a "guy who cares deeply about his family, a man with compassion and vision."

"There is no one you would rather go to a Springsteen concert in Jersey with than him," Walz said as the audience shouted, "Bruce."

Tuesday's Harris-Walz event kicks off a five-day campaign road trip that will visit seven crucial swing states.

The vice president and Walz are scheduled to visit Eau Claire, Wisconsin; Detroit, Michigan; Durham, North Carolina; Savannah, Georgia; Phoenix, Arizona; and Las Vegas this week.

Walz says he 'can't wait' to debate JD Vance: 'These guys are creepy'

Gov. Walz came out hard against former President Donald Trump and his running mate Sen. JD Vance during his first campaign rally speech as Harris' vice presidential pick.

"Donald Trump's not fighting for you or your family," Walz said. He never sat at that kitchen table, like the one I grew up at, wondering how we were going to pay the bills. He sat at his country club in Mar a Lago wondering how he can cut taxes for his rich friends," Walz added.

Turning his attention to Vance, Walz said, "His running mate shares his dangerous and backward agenda for this country."

"I got to tell you, I can't wait to debate the guy," Walz continued, quipping, "That is, if he's willing to get off the couch and show up."

Calling out the Republican ticket, Walz added, "These guys are creepy. And yeah, it's just weird as hell."

JD Vance holds event in Philadelphia

Republican vice presidential nominee JD Vance is aiming to tie what he portrays as Harris' failures along the U.S.-Mexico border to deaths from drug addiction.

Vance told several hundred supporters gathered in a South Philadelphia event space that, "thanks to the policies of Kamala Harris, you've got children who've been orphaned" when their parents die from drugs.

Several Pennsylvanians shared personal stories of how addiction issues have impacted their families.

As he has over several speeches and interviews in recent weeks, Vance told his own story related to drug addiction, noting that his mother has been drug-free for a decade but, as a child, he was "desperately hoping and praying, Jesus, please let her wake up from this."

U.S. government data undercuts the claim that people seeking asylum and other border crossers are responsible for drug trafficking. At a hearing last year, James Mandryck, a U.S. Customs and Border Protection deputy assistant commissioner, said 73% of fentanyl seizures at the border since the previous October were smuggling attempts carried out by U.S. citizens, with the rest being done by Mexican citizens.

Trump reacts to news Harris picked Tim Walz

Republican presidential candidate Donald Trump reacted to the news that Harris picked Walz as her running mate.

Trump, in a campaign email, claimed Walz "would be the worst VP in history" and said the governor was "even worse" than Harris.

"Just like Kamala Harris, Tim Walz is a dangerously liberal extremist, and the Harris-Walz California dream is every American's nightmare," Trump's campaign said.