The measures were driven by surging numbers of daily infections, rising hospitalisations and ominous spikes in the rate of Covid diagnostic tests returning positive.
The onset of winter, with people more likely to congregate indoors, will only worsen the trends, experts say.
California on Thursday became the second state, after Texas, to see its tally of confirmed infections to date climb above one million.
As a record 60,000 Americans were hospitalised with the disease over a single day, Dr Anthony Fauci expressed his concern for his fellow countrymen.
The United States faces a “challenging and ominous” winter as it battles to control a surging number of coronavirus cases, the country’s top infectious diseases adviser said.
READ MORE: ‘Ominous’ winter ahead as US Covid cases surge, warns Fauci
Total cases across the United States hit an all-time daily high for a third straight day on Thursday, reaching at least 160,000, and crossing the 100,000 mark for a ninth consecutive day, Reuters data showed.
The number of people hospitalised with the virus surged to at least 66,500 by late Thursday, the highest ever for a single day during the pandemic.
The death toll rose by at least 1,170 to a total of 242,979.