Few incoming presidents have faced such a daunting in-tray. Joe Biden signalled in advance his top priorities on day one. The most pressing - tackling the Covid crisis.
From now face masks and social distancing are mandatory in all federal buildings. There are new orders to accelarate the vaccination programme and redoubled efforts to push a stimulus package through Congress.
This will bring much needed relief to hard-pressed American families and struggling industries.
"The first priority will be to ensure that coronavirus relief efforts are embedded as much as possible into US policies. So we'll be looking to see this 1.9 trillion dollar package that Biden proposed a couple of days ago, launching initial discussions through Congress and speeding up vaccination efforts as much as possible, potentially kind of through executive action," Cailin Birch , Global Economist, Economist Intelligence Unit, London said.
Rejoining the Paris Climate accords - which Trump withdrew the US from - was a campaign pledge . Biden will deliver on this promise through a batch of executive orders.
"The US will rejoin the Paris Accords and try to send a signal to the world that they'll be taking climate change seriously, deadly seriously for the next four years, building that into all the public investment programmes that Mr Biden would like to make happen," Cailin Birch , Global Economist, Economist Intelligence Unit, London said.
Biden will also end Trump's ban on arrivals of foreigners from several Muslim countries. The new administration will replace it with improved screening of visitors and information sharing with foreign governments.
Then work stops immediately on Trump's cherished border wall, the money redirected to other priorities.