Donald Trump took power as the 45th president of the United States on Friday and pledged to end what he called an "American carnage" of rusted factories and crime in an inaugural address that was a populist and nationalist rallying cry.
Striking a defiant tone, Trump said the American middle class has been devastated by the outsourcing of jobs abroad.
"From this moment on, it's going to be America First," the Republican told thousands of people gathered on the grounds of the National Mall as he took from Democrat Barack Obama.
With Obama and three other former presidents sitting nearby, Trump accused previous U.S. administrations of enriching Washington at the expense of struggling American families.
Underscoring the deep divisions in the country, protests against Trump turned ugly in downtown Washington. Black-clad activists smashed store windows, blocked traffic and fought with police in riot gear who responded with tear gas and stun grenades. CNN reported that 90 people had been arrested.