With the U.S. Capitol encircled by thousands of armed troops two weeks after a mob laid siege to it, Biden took the oath of office administered by U.S. Chief Justice John Roberts and became the oldest U.S. president in history at age 78.
"We must end this uncivil war that pits red against blue, rural versus urban, conservative versus liberal. We can do this - if we open our souls instead of hardening our hearts."
The scaled-back inauguration ceremony was stripped of much of its usual celebratory spirit. The National Mall, typically packed with throngs of supporters, instead was filled with U.S. flags in a reminder of the pandemic Biden will confront as chief executive.
Speaking on the steps of the Capitol, where supporters of then-President Donald Trump clashed with police in a chaotic assault that left five dead and stunned the world on Jan.6, Biden cast his ascension as proof that the attackers had failed to disrupt the underpinnings of American democracy.