According to the U.S. Constitution, Barack Obama's presidency ended at noon on Jan. 20 allowing the U.S. president-elect to assume the office. A few minutes later Trump took oath of office during the inauguration ceremony on the steps of the Capitol in Washington.
U.S. Chief Justice John Roberts administered the presidential oath.
Some events took place on Jan. 19. Donald Trump and U.S Vice-President Elect Mike Pence laid wreaths at the Tomb of the Unknown Soldier in Arlington National Cemetery. The access to the ceremony was granted only to the family members of the top officials, Administration members and accredited journalists.