After a storm-related delay of nearly two hours, Trump appeared on the National Mall in Washington on Saturday to deliver a speech that mixed broad appeals to patriotism with pointed attacks on perceived ideological threats at home and abroad.
During the "Salute to America" event, Trump lauded American achievements such as war victories, the lunar landing and the Wright brothers' pioneering flight, as well as the US system of government in general.
But he also urged Congress to pass stalled the SAVE America Act, legislation that would limit mail ballots and require proof of citizenship to register to vote.
Trump also leaned into partisan territory unusual for an Independence Day address, which presidents typically use to unify the country.
He highlighted his support for the Second Amendment and revived denunciations of communism, which are becoming an increasingly central part of Trump's message ahead of the November mid-terms.
"We like to stop a threat like that immediately and before it begins. It's like a cancer - you've got to cut it out and you got to cut it out fast," he said.
The speech capped a holiday that Trump has gone to great lengths to shape to his own tastes.
The event organisers were largely aligned with the White House, supplanting a bipartisan organisation.
"We will always be on top," Trump said.
"We will never let our country fall. We will always be the best."
Trump didn't talk about himself as much as he usually does in rally speeches. Still, he still found time to include a joke about seeking a third presidential term and about World War II's "greatest generation".
"They are the greatest generation," Trump said. "I hate to admit that, but they are."
Anticipation for the milestone holiday has been building for much of the year, serving as an opportunity for Americans to reflect on their complicated history as one time colonists of an empire who became a superpower of their own.
Organisers of celebrations months in the making had to adjust or cancel activities entirely as much of the East Coast sweltered under heat that approached and in many cases surpassed triple digits.
Severe weather prompted the cancellation of celebrations in Hartford, Connecticut, along with Harrisburg and Wilkes-Barre, Pennsylvania.
Spectators at Boston's fireworks and concert were told to briefly seek shelter before events later resumed. An evacuation was also ordered in Philadelphia. New York and Pittsburgh moved forward with fireworks but shifted the time to accommodate the shifting weather.
The disruption was particularly acute in Washington, where crowds were building at the National Mall several hours before the evacuation.
Tina Hale, 58, of Cohoes, New York, watched three of her grandchildren children dip their hands into a pool of water near a museum. Hale pointed toward the sky and urged them to look up as three military jets roared above the crowd.
"If that doesn't make you proud to be an American," she said.
David Koshko, 42, and his wife, Jennifer Koskho, of Harrisburg, Pennsylvania, came to Washington for a baseball game but planned to stay for the city's fireworks show.
"Just to be a part of the 250 years (anniversary) is an amazing thing," said David Koshko, a commercial driver and veteran of the Marine Corps reserves.
In New York, tall ships, with their masts, rigging and white sails outlined against a blue sky, made a procession around the Statue of Liberty and up the Hudson River, recalling the fanfare around America's 200th anniversary in 1976.
The 43 ships were followed by a display of aerial might with a stealth bomber and the Navy's Blue Angels. Patrouille de France, the French Air Force's acrobatic teams, flew over New York Harbor with their red, white and blue trails, evoking images of the American flag.
At George Washington's Mount Vernon, people took the Oath of Allegiance to become US citizens. They stood with eyes closed and hands over hearts for the national anthem.
with Reuters
