Pete Buttigieg attracted a packed house of several thousand supporters on Sunday as he formally announced his candidacy for president of the United States.

Although Buttigieg, 37, has been in the thick of the 2020 race for several weeks, he made it official in South Bend, Ind., the city he has led as mayor since 2012. The large crowd in attendance added legitimacy to talk that Buttigieg is a serious candidate for the Democratic presidential nomination.

“We’re at capacity inside the Studebaker building, but spirits are high out in the overflow area,” Buttigieg tweeted several hours before the event.

The South Bend Fire Marshal said there were more than 6,000 people in attendance.

“Crowd estimates for this Buttigieg announcement, per the fire marshal: Inside there were 4,526 people. Outside in the overflow was an additional 1,500,” Politico’s Daniel Strauss tweeted.

[Read more: 2020 Dems: Buttigieg leapfrogs Warren, Harris, O'Rourke to No. 3]

"Crowd size for @PeteButtigieg kickoff: 4,526 inside and more than 1,500 outside in the overflow crowd, according to the South Bend Fire Marshall," NBC News reporter Josh Lederman tweeted.

According to Edward-Isaac Dovere, a staff writer at the Atlantic, Buttigieg's "hometown" tally ranks fourth among candidates for the 2020 Democratic presidential nomination.

During his speech, Buttigieg hailed the progress in South Bend that was made during his tenure as mayor and billed himself as the candidate uniquely qualified to take on President Trump.

“The horror show in Washington is mesmerizing, all-consuming,” Buttigieg said. “But starting today, we are going to change the channel.”

Buttigieg launched a presidential exploratory committee in January and, in the months since, has traveled to early primary states to introduce himself to voters. He announced this month that his campaign raised $7 million for the first quarter of 2019, an impressive haul that outpaced the majority of his Democratic competitors.

Though Buttigieg joins an already expansive field of Democrats who are running to take on Trump in 2020, he has begun to gain in popularity in recent weeks.

A pair of new polls from Iowa and New Hampshire showed Buttigieg surging among the Democratic candidates, coming in third behind former Vice President Joe Biden and Sen. Bernie Sanders, I-Vt.

“Change is coming, ready or not,” Buttigieg said during his speech. “The question of our time is whether families and workers will be defeated by the changes beneath us or whether we will master them and make them work toward a better everyday life for us all. Such a moment calls for hopeful and audacious voices from communities like ours. And yes, it calls for a new generation of leadership.”

If elected in 2020, Buttigieg would be the youngest and first openly-gay president.

“Are you ready to turn the page and start a new chapter in the American story?” Buttigieg asked the crowd. “If you join me, if you and I rise together to meet this moment, one day they will write histories, not just about one campaign or one presidency, but about the era that began here today in this building where past, present, and future meet, right here this chilly day in South Bend.”

Buttigieg took several shots at Trump during his speech, including in telling the crowd he sought “to tell a different story than ‘Make America Great Again.’”

"We live in a moment that compels us each to act,” he said. “The forces changing our country are tectonic — forces that help to explain what made this current presidency even possible. That's why this time it's not just about winning an election — it's about winning an era."