Race cars have roared through the streets of Washington, DC, in the shadow of its landmarks as the Freedom 250 Grand Prix, created by United States President Donald Trump, has kicked off.

Before Sunday’s first-of-its-kind race, IndyCar drivers tested open-wheel cars at speeds of up to 298 kilometres per hour (185 miles per hour) on Saturday over the bumps and bends of a seven-turn, 2.7km (1.7-mile) course that winds around the Washington Monument, the US Capitol, the National Gallery of Art and the Smithsonian National Air and Space Museum along the National Mall.

Spain’s Alex Palou, the championship leader with six wins this season, claimed his seventh pole position of the campaign with a qualifying lap of 56.899 seconds after setting the fastest practice time of 56.614 seconds.

But results took a back seat to the dramatic backdrop for Sunday’s race, which Trump established by executive order as part of celebrations marking the 250th anniversary of the US.

Organisers expected up to 100,000 people to attend, including Trump.

A field of 25 drivers contested 147 laps on Sunday over a total distance of 400km (250 miles), making it the second-longest street race in IndyCar history after 500km (310-mile) events held in Cleveland in 1982 and 1983.