The media weren't the only people surrounding the center, though. Demonstrators were sprinkled amongst the crowd.
"If you look across, you see the First Amendment banner right there," said Tim Smith who traveled to the city from Gettysburg, Pennsylvania.
In the birthplace of liberty, people have the liberty to express their opinions. That's just what demonstrators like Smith chose to do.
"I've been following politics with my art now for a while so I knew this was an absolutely historic moment," said Smith.
He was holding a large sign that said "LOSER" written in the font often used for former President Donald Trump's campaign.
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Smith told Action News supports Vice President Kamala Harris in the election.
Michael Turner of Port Richmond says he supports Trump. Turner also came out to Independence Mall the in afternoon before the debate.
"Just to show support and get along. See what the people have to say. Nothing more, nothing less," Turner said.
Realizing the debate would draw protest groups large and small, Philadelphia police began preparations a while back.
Barricades go up, security tightens in Philly for Harris/Trump presidential debate
"We are prepared for this," said Philadelphia Police Commissioner Kevin Bethel in an exclusive interview with Action News Anchor Sharrie Williams. "We have been working in collaboration with our federal partners."
Securing the site of the presidential debate is something Bethel says his officers are focused on. Philadelphia police are working with federal authorities to secure the area, which has been blocked off.
The interior perimeter of the area near the Constitution Center, which is surrounded by a double layer of fencing with concrete blockades, is protected by the Secret Service.
The area outside of that perimeter is also protected by the Secret Service.
There's no public access to the National Constitution Center or the Independence Visitors Center. The sidewalks along Market Street are blocked off.
Bethel says officers won't disrupt anyone's First Amendment rights as long as their behavior doesn't break the law.
"We expect to have multiple different groups protesting," he said. "We'll give them all the latitude to do that. If they engage in criminal behavior, that'll change our posture."
'The ABC News Presidential Debate | Race for the White House' will air September 10 at 9 p.m. It will air on ABC and stream on 24/7 streaming network ABC News Live, Disney+, and Hulu.