Trump, virus and protests: Here is how Fourth of July celebrations unfolded!

Across the country, virus fears dampened or nixed Main Street parades, backyard barbecues and family reunions on a day when Americans typically celebrate their 1776 declaration of independence from Britain.

Instead of adopting a unifying tone, Trump -- facing a tough re-election and eager to mobilize his political base -- railed against protesters demanding racial justice after unarmed African American George Floyd was killed by a white police officer.

"We are now in the process of defeating the radical left, the Marxists, the anarchists, the agitators, the looters," Trump said.

Just steps from where Trump spoke, peaceful protesters marched down blocked-off streets around the White House, Black Lives Matter Plaza and the Lincoln Memorial. They were confronted by counter-protesters chanting, "USA! USA!" but there were no reports of violence.

Millions of Americans have been demonstrating against police brutality and racial inequality since the May 25 killing of George Floyd, a 46-year-old Black man who died after a white Minneapolis police officer knelt on his neck for nearly nine minutes. In addition to achieving police reforms in some cities, some protesters have removed Confederate statues and other symbols of America's legacy of slavery.

Speaking from the White House lawn, Trump addressed a crowd that included frontline health workers battling COVID-19, which has killed nearly 130,000 Americans.

He accused China -- where the outbreak originated -- of a cover-up that allowed the illness to race across the globe, but hailed American "scientific brilliance."

Fireworks displays are typically a high point of the holiday, but an estimated 80 per cent of the events have been canceled this year.

Stellar fireworks on US independence day. NASA flaunts the universe! NASA releases images captured by Hubble telescope.

They tweeted: "Happy #FourthofJuly!  Red, white, and blue colors are found in this Hubble image of a supernova remnant found in the Large Magellanic Cloud, a dwarf galaxy that lies close to the Milky Way."

Washington was hosting a fireworks show on the National Mall, and some said they were compelled to come at a moment when the US is both grappling with the virus and undergoing a historic reckoning on racism.

Just months before November's presidential election, opinion polls in key states show Trump trailing his Democratic rival, former Vice President Joe Biden. Biden wrote a Fourth of July opinion piece that struck a contrasting note with the Republican president and accused him of finding "new ways to tarnish and dismantle our democracy" every day.

NASA astronauts observe Fourth of July from space.