An evacuation was ordered on Saturday evening at the National Mall as storms gathered around Washington just hours before US President Donald Trump was scheduled to deliver a speech commemorating America’s 250th anniversary of independence.Those on the Mall were encouraged to go to federal buildings nearby or Smithsonian museums.“Freedom 250 will share updates on programming and doors reopening,” Freedom 250 spokeswoman Danielle Alvarez said in a statement.Plans for fireworks were still moving forward in other cities including Chicago and New York, where tall ships passed the Statue of Liberty earlier in the day, recalling the fanfare around America’s 200th anniversary in 1976.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.Air Force One takes part in a flyover at a Salute to America Independence Day event at the National Mall in Washington on Saturday. Photo: APOrganisers 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.