WASHINGTON — President Donald Trump ushered in the 250th anniversary of American independence on Friday with soaring rhetoric about American exceptionalism before veering into a darkly political speech with warnings about a sinister threat of communism that evoked one of the country’s ugliest chapters.

“Communism is a mortal threat to American liberty,” he said from Mount Rushmore. “It is the greatest threat to our country, including World War I, World War II, Pearl Harbor or even 9/11.”

While the language was similar to several other speeches Trump has given in recent days, it was notable for being delivered in a national park that commemorates some of America’s most prominent presidents. And it swerved from the typically apolitical, unifying speeches past presidents like Gerald Ford or Ronald Reagan have delivered during earlier high-profile Independence Day celebrations.

Indeed, Trump’s language evoked the Red Scare of the 1950s, when alleged communists were persecuted and blacklisted from jobs across America, from Washington to Hollywood.

In New York City, Mayor Zohran Mamdani, a democratic socialist, delivered his own address that cast America as a nation of contradictions “working each day towards the perfection in which it was conceived.”

The president’s speech capped an Independence Day eve that was otherwise most notable for a brutal heat wave the gripped much of the eastern portion of the country. Officials have warned those celebrating the holiday to stay hydrated and take air-conditioned breaks as needed.

Philadelphia canceled its Salute to Independence parade Friday. The Great American State Fair in Washington shut down in the early afternoon before reopening at 5 p.m. The Capitol Fourth concert, a mainstay of the holiday in Washington, opened its gates a little later than normal but ultimately moved forward with appearances from Patti LaBelle, Trace Adkins, members of the Artemis II space mission and fireworks over George Washington’s Mount Vernon. An Independence Day parade scheduled for Saturday in Washington was canceled.

Looking for a place to cool off

By early afternoon Friday in Washington, hundreds of people were roaming the grounds of the National Mall, home to The Great American State Fair. They snapped photos of the flyovers and tried to cool off inside tents that offered $9 lemonades and $23 turkey legs. Many were dressed in patriotic colors, their faces glistening with sweat.

Glenn Brooks, who was pardoned by Trump for his participation in the Jan. 6, 2021, attack on the Capitol, said he was “thankful to be participating in this grand event.”

The activity culminates in the main event Saturday, when fireworks will erupt in communities across the U.S., along with backyard cookouts and block parties. Trump will deliver another speech at the National Mall in Washington before what is being billed as a historically massive fireworks show.

As the rest of the country struggled under stifling heat, the Pacific Northwest enjoyed temperatures in the 60s with even a few light showers.

World Cup soccer fans in Seattle were staying cool Friday as they got psyched up for Monday’s big game between the U.S. and Belgium. In the nearby suburb of Issaquah, Megan Kurowski, 31, brought her two dogs to the dog park so they could get some exercise before she went to work.

Kurowski said she was feeling positive about America’s 250th anniversary and was planning a possible paddleboard to watch the fireworks.

“Everyone’s just, from what it seems, been pretty excited about celebrating 250 years,” she said.

The holiday is unfolding at a unique time in the U.S. The anniversary has served as an opportunity for the country to reflect on its history while also reminding it of the political polarization of the moment.

On a holiday of unity, there is an undercurrent of division

In New York, Mamdani, a Democrat, did not mention Trump by name, but parts of his speech appeared aimed at the president’s divisive rhetoric.

“For generation after generation, we have been told that when the world has sent its people to our shores, it has not sent its best,” Mamdani said in an apparent reference to a common criticism from Trump. “Those ideals upon which our nation was built — they are strong enough to endure any authoritarian regime, but only if we reach for them.”

Freedom 250, an organization aligned with the White House, has come to rival America250, a bipartisan group founded by Congress a decade ago. Freedom 250 has organized much of the activity in Washington, including the Great American State Fair. America250 is behind the ball drops unfolding in many cities, including New York, and will host a concert in Los Angeles on Saturday.

About 4 in 10 U.S. adults feel “proud” about the country’s 250th anniversary, according to an April survey from The Associated Press-NORC Center for Public Affairs Research. Roughly 3 in 10 said “excited” describes their emotions.

Ahead of the holiday, auto technician Joe Fuqua-Bejarano in Topeka, Kansas, sized up “what makes us awesome” as a people. It is clearly not the politics, in his view, but rather resilience.

“We’ve just all got to find unity somewhere, whether that’s in laughter or perseverance, and keep everybody cool,” he said from the fireworks stand where he is doing a booming business as a side hustle.

Christina Zhou, a 25-year-old research assistant from Cambridge, Massachusetts, said she would aim to “think about just things that are happening locally.”

“It feels a little bit more like within our own personal control,” she said.

Jerry Chin of Newcastle, Washington, said he wasn’t aware that the U.S. was celebrating its 250th anniversary and planned to stay low-key around the holiday. He and his wife generally skip the fireworks and instead stay home with their fearful dogs to keep them calm.

“America’s a great place, but there are some concerns,” he said. Chin, 55, and his wife worry about healthcare and issues around staying healthy, but they also stress about politics.

“We’re Democrats, so kind of given up hope,” he said. “Just feel that it is the way it is. I don’t know if there could be change.”

At the National Archives in Washington, visitors made their way through the Rotunda to look at the Declaration of Independence, the Constitution and the Bill of Rights — and to escape the heat outside.

Michael Dresdner, 60, traveled from West Orange, New Jersey, with his wife, Cindi, 57, and about two dozen other people to be part of the America 250 celebrations. He said their group of travelers included people on both sides of the political aisle — and that is what gave him hope for the future of American democracy.

“We are all here, and we all love America,” he said.