New Jersey's governor was expected on Saturday to follow four other states - California, New York, Illinois and Connecticut - demanding that millions of Americans close up shop and stay home to slow the spread of coronavirus infections.
The sweeping state-by-state public health restrictions, unprecedented in breadth and scope, added to the distance being experienced among ordinary Americans even as the pandemic seemed to close in on the highest levels of power in the nation's capital.
An aide to US Vice President Mike Pence, leading the White House task force formed to combat the outbreak, tested positive for the virus, but neither President Donald Trump nor Pence have had close contact with the individual, Pence's press secretary, Katie Miller, said in a statement on Friday.
Pence's office was notified of the positive test on Friday evening, and officials were seeking to determine who the staffer might have exposed, Miller said.
The aide was not publicly identified, and the vice president's office did not immediately respond to a request for further details of the diagnosis, the staffer's condition, or whether Pence would be tested.
The White House said last week that Pence did not require testing after dining with a Brazilian government official who later tested positive for the respiratory illness. President Donald Trump has tested negative for the virus, his doctor said last week.
Two members of the US House of Representatives tested positive for on Wednesday, becoming the first members of Congress known to have contracted the disease, which has killed 266 people in the United States.
The total number of known US coronavirus cases has risen exponentially in recent days, climbing past 18,000 in a surge that health officials attributed in large part to an increase in diagnostic testing.
SOCIAL-DISTANCING GOES STATEWIDE
Expanding on social-distancing measures increasingly adopted at the local level, California Governor Gavin Newsom instituted the first statewide directive requiring residents to remain indoors except for trips to grocery stores, pharmacies, gas stations and other "essential businesses."
Newsom's order, announced late on Thursday, made allowances for the state's 40 million people to briefly venture outside for exercise so long as they kept their distance from others.
On Friday, his counterparts in New York state, Illinois and Connecticut followed suit, and New Jersey Governor Phil Murphy said he planned to issue similar directives on Saturday.
The five states where governors have banned or will soon ban non-essential businesses and press residents to stay inside are home to 84 million people combined, about a quarter of the entire US population and account for nearly a third of the nation's economy.
The state directives were for the most part issued without strict enforcement mechanisms to back them up.
"Summons and arrests is an option, but obviously that's a last resort," New York City Police Commissioner Dermot Shea told reporters on Friday, saying authorities would focus on urging New Yorkers to follow the new rules.
In New York City's Central Park, several bikers and joggers were on the pathways, mostly alone but a few in pairs.
"It's real and it's scary, I hate it," said physical therapist Kerry Cashin, 49, of the stay-at-home order. "I feel like I always knew it was going to go this way, but it made me scared."
'OVERBLOWN' OR 'UNDERSTANDABLE'
Barbara Heller, 52, who lost jobs singing opera and working for a catering company earlier in the week, called the stay-at-home order "ridiculous."
"This whole thing has been a little bit overblown," she said. "It's serious, but I think this is beyond extreme."
Just two dozen people milled outside Hollywood's Dolby Theatre in Los Angeles, home of the Oscars and normally teeming with hundreds of tourists.
Zane Alexander, 27, recently laid off from a medical marijuana dispensary, said he was on his way to pick up his last paycheck "until Lord knows when."
"It's totally understandable," Alexander said, adding, "I sure wish it weren't the case."
Retiree Jerry Rasmussen, 73, sat on a sunny public bench reading the San Francisco Chronicle in that city's Cole Valley neighbourhood, with hand sanitizer, gloves and a mask beside him.
"I figure being outdoors like this is pretty safe, as long as I'm not too close to anyone," he said.
Even before the flurry of statewide stay-at-home orders, the coronavirus pandemic had virtually paralysed parts of the US economy and upended lifestyles over the past week, as school districts and colleges cancelled classes and many companies were shuttered, either voluntarily or by local government mandates.
Washington state, which documented the first known US coronavirus case in January and now accounts for the greatest number of deaths - 83 as of Friday - has since March 16 closed bars, restaurants, recreation venues and entertainment facilities, while banning all gatherings of more than 50 people.