The United States marked 250 years since the Declaration of Independence on Saturday, as a record-breaking heatwave forced the cancellation of Washington's traditional parade and delayed the opening of the Great American State Fair on the National Mall. Forecasters reported that heat-index values reached 46°C in the capital, leading to at least 44 medical emergencies at the fair on Friday and prompting authorities in Philadelphia, Leesburg and other towns to scrap parades and concerts. Organisers cited ‘safety concerns’ after the National Weather Service issued an extreme heat warning for the District of Columbia, while utility failures and storms left hundreds of thousands without power across the Northeast and Midwest.

From the Black Hills of South Dakota to the Lincoln Memorial, President Donald Trump placed himself at the centre of the semiquincentennial, delivering a dark speech at Mount Rushmore on Friday in which he warned of a ‘resurgence of the communist menace’ and accused domestic ‘radicals and extremists’ of waging a ‘renewed attack’ on American identity. The address, which linked left-wing Democratic primary victories and recent immigrants to a ‘mortal threat’, was followed on Saturday by a campaign-style rally on the National Mall, where Trump promised a ‘really long’ speech and touted the largest fireworks display in history. White House officials said the president would celebrate the nation’s founding and highlight his administration’s achievements, but the events were organised by Freedom 250, a Trump-backed nonprofit that largely sidelined the bipartisan America250 commission established by Congress a decade earlier.

The partisan staging drew sharp criticism. Several Democratic-led states refused to send delegations, and multiple musical acts withdrew, citing concerns over politicisation. A Reuters/Ipsos poll found that a majority of Americans, including nearly three-quarters of Democrats, believed the 250th-anniversary events had become excessively political. In a counterpoint, Pope Leo XIV, the first US-born pontiff, used the occasion to defend the contributions of immigrants to American society, while King Charles III spoke of defending shared values between the two countries. Meanwhile, a march by hundreds of masked members of the white nationalist Patriot Front, who carried Confederate flags through the capital chanting ‘reclaim America’, further illustrated the tensions coursing through the public holiday.

The anniversary unfolded as the nation also hosted World Cup matches and as Trump pressed his party to support the SAVE America Act ahead of November’s midterm elections. The severe heat, which climate researchers from World Weather Attribution described as virtually impossible without human-caused climate change, tested infrastructure from New Jersey to New England, with transmission operators asking consumers to reduce electricity use. While the evening speech and fireworks went ahead, America’s 250th birthday exposed the political and physical fissures that now run through the republic, with the midterm elections looming as the next major test of the public mood.