US President Donald Trump plans to speak on the National Mall in Washington DC ahead of what is being billed as a historically enormous fireworks show that will rain down over the capital.
Hundreds of masked members of the white nationalist group Patriot Front marched through parts of the capital, ahead of Independence Day festivities planned for the evening that have been criticised as divisive.
The group posted on social media about 400 members had arrived in the capital, and Reuters photographers saw hundreds of people dressed in Patriot Front outfits travelling on DC Metro trains.
Videos posted on various social media platforms and shared on Patriot Front's own Telegram channel showed the group marching to drummers near the US Capitol and the Union Station transit centre while wearing khaki pants and caps, blue shirts, white face coverings and sunglasses.
Many were carrying the group's flag, Confederate flags, and variations of the US flag, at times chanting "Reclaim America".
Patriot Front, known for its uniforms, face masks and flash-mob-style demonstrations, formed in 2017 after the deadly "Unite the Right" rally in Charlottesville, Virginia,
The president was in South Dakota at Mount Rushmore on Friday, where he delivered a dark speech about the threat of communism in the US as the chiselled images of four of his most prominent predecessors loomed behind him.
Elsewhere, fireworks are scheduled to be set off on Saturday over Navy Pier in Chicago and against the skyline of New York City.
New York hosted a ball drop at midnight to usher in the holiday with the same fanfare as New Year's Eve and tall ships paraded past the Statue of Liberty in a call back to the fanfare around the 200th anniversary in 1976.
Bristol, Rhode Island, describes itself as home of the country's oldest Independence Day celebrations dating to 1785.
In Los Angeles, Queen Latifah will host a concert featuring performances by The Smashing Pumpkins and Chris Stapleton.
Chaka Khan is billed as a special guest.
Anticipation for the milestone holiday has been building for much of the year, serving as an opportunity for people across the US to reflect on their complicated history as one-time colonists of an empire who became a superpower of their own.
The country is celebrating 250 years since 13 colonies declared independence from Britain, triggering the Revolutionary War that ended with officials in London recognising US sovereignty in 1783.
Celebrations months in the making had to adjust or cancel activities entirely as much of the east coast sweltered under heat.
In Washington DC, the Great American State Fair was closed for several hours on Friday afternoon during the worst of the heat.
The city's main Independence Day parade scheduled for Saturday was cancelled but a smaller one rolled along in the Capitol Hill neighbourhood in the morning as onlookers sought shade under trees along the route.
To the chagrin of many on the east coast, the weather was downright pleasant on the other side of the country.
The Pacific Northwest enjoyed temperatures of about 20C on Friday with a few light showers.
Plenty of other American pastimes are overlapping with the holiday.
More than a dozen Major League Baseball games are on the schedule for Saturday.
The World Cup, being hosted in the US for the first time in 32 years, will have matches in Houston and Philadelphia on Saturday following a nail-biter overtime win by Argentina over Cape Verde on Friday outside Miami.
Pop culture enthusiasts can obsess over Taylor Swift's Friday wedding to football player Travis Kelce at New York City's Madison Square Garden.
And Madonna released her 15th studio album, a collection of dance tracks.
The celebrations are unfolding against the backdrop of a deep divide this election year that has been expanding for years, visible in everything from political expression to cultural norms to age-old questions over race, class and immigration.
with Reuters
