The number of cases is by far the highest in the world but health officials believe that for every reported case, there are roughly 10 times as many people infected, given the limits on testing and the large number of mild infections that have gone unreported or unrecognised.
The bleak milestone was reached as new cases in the US stand at about 54,000-a-day.
While that is down from a peak of more than 70,000 in the second half of July, cases are rising in nearly 20 states, and deaths are climbing in most.
Many Americans have resisted wearing face masks and social distancing.
The United States’ failure to contain the spread of coronavirus has been met with astonishment and alarm in Europe.
Italians were unprepared when the outbreak exploded in February, and the country still has one of the world’s highest official death tolls at 35,000.
But after a strict nationwide, 10-week lockdown, vigilant tracing of new clusters and general acceptance of mask mandates and social distancing, Italy has become a model of virus containment.
Much of the incredulity in Europe stems from the fact that the US had the benefit of time, European experience and medical know-how to treat the virus that the continent itself did not have when the first Covid-19 patients started filling intensive care units.
Italian health minister Roberto Speranza has not shied away from criticising the US, officially condemned Washington’s decision to withhold funding from the World Health Organisation and has expressed amazement at President Donald Trump’s virus response.
After Mr Trump finally donned a mask last month, Mr Speranza said: “I’m not surprised by Trump’s behaviour now; I’m profoundly surprised by his behaviour before.”
More than 162,000 have died from the virus in the US and European nations have barred American tourists and visitors from other countries with growing cases from freely travelling to the bloc.
France and Germany are now imposing tests on arrival for travellers from “at risk” countries, including the US.
“I am very well aware that this impinges on individual freedoms, but I believe that this is a justifiable intervention,” German health minister Jens Spahn said last week.
Mistakes were made in Europe, too, from delayed lockdowns to insufficient protections for nursing home residents and critical shortages of tests and protective equipment for medical personnel.
The virus is still raging in some Balkan countries, and thousands of maskless protesters demanded an end to virus restrictions in Berlin earlier this month.
Hard-hit Spain, France and Germany have seen infection rebounds with new cases topping 1,000 a day, and Italy’s cases inched up over 500 on Friday.
The UK is still seeing an estimated 3,700 new cases a day, and some scientists say the country’s pubs might have to close again if schools are to reopen in September without causing a new wave.
Europe as a whole has seen more than 207,000 confirmed virus deaths, by Johns Hopkins’ count.
