At a church on Sunday in a suburb of Washington, D.C., where the pews are filled each week with dozens of active and retired federal workers, the weight of the government shutdown hung in the air. The Rev. Krishnan Natesan, pastor of Hemingway Memorial A.M.E. Church in District Heights, Md., delivered a sermon about holding on to faith and hope amid uncertain futures. “People are under high stress,” he said in an interview after services.

The day before, while traveling through Dallas Love Field Airport, Mike Talbert, 66, an industrial supplies buyer visiting from Wisconsin, did not notice any effects on his travel and shrugged off potential consequences of the shutdown. “It’ll get figured out,” he said.

As the first full week of the shutdown began, a split screen of reactions played out across the country. Many people said that they had yet to feel a significant impact aside from the closing of some tourist sites. Air travel has been largely uninterrupted so far. And many Americans have not experienced a change in their everyday lives.

Others, especially those in the federal work force, were bracing for layoffs or firings, seeing initial signs of economic fallout or anxiously wondering what was in store the longer this lasted.

And for still others, the shutdown felt like the latest twist of turbulence in a vortex of change as President Trump has dramatically reordered many aspects of American life. Collectively, the reactions offered one more reflection of a divided America.

“It’s a scary time — obviously we all want the best, but I feel like we’re going down a very dark road,” Scott Nichols, 55, a real estate broker from Ellijay, Ga., said as he stood outside a closed museum at the Gateway Arch National Park in St. Louis. “And it’s not just political. Like, as a society we’re a little broken right now.”

Mr. Nichols was among the travelers and locals who visited national parks, historical sites and monuments around the country on Saturday, only to find locked doors and closed signs in one of the most immediate effects of the shutdown. Disappointments abounded, but not a sense of urgency.

On Friday in downtown Atlanta, however, a more tangible impact was being felt at a Thai restaurant across the street from the towering Richard B. Russell Federal Building and U.S. Courthouse.

Cholada Untachantr, the manager at Tyde Tate Kitchen, said the business relied on the weekday lunch rush, which includes federal employees. “We’re directly affected,” Ms. Untachantr said. “We thrive from the governmental building office employees, and we noticed a slowdown.”

While federal budget clashes are not uncommon, this shutdown — the first since the 35-day shutdown that began in December 2018 — is unfolding in an especially fraught period in which 300,000 federal employees have been projected to leave the government by the end of the year and in which the Trump administration has signaled that more layoffs could begin during the impasse.

Carmella Long, 50, of Clinton, Md., said she was not yet affected by the shutdown in her role at the Food and Drug Administration. But previous staff cuts have meant added responsibilities for her and her remaining colleagues. The furloughs, she fears, will only make work harder.

“It’s like being an emotional hostage,” Ms. Long said. This year, she began medical treatment for anxiety caused, in part, by the stress of the Trump administration’s mass layoffs, she said. “I don’t know from one minute to the next whether I’m going to blow up,” she said.

Lewis Washington, a 76-year-old Air Force veteran in Virginia, who flew to Atlanta on Saturday, said he worried for federal employees, including military service members, who were working without pay. “It will hurt,” he said.

But for Joana Marinova, 29, a resident of Atlanta’s Buckhead neighborhood, all the strain and pressure are necessary in the long run.

“A disruption is painful while it’s happening, and it’s been a whole nine months of this,” Ms. Marinova said. “But it’s necessary, because if we don’t control the spending of the government and all the waste, fraud and abuse of tax dollars, our deficit goes up.”

For some Americans, the shutdown is a predictable result of a hopelessly fractured political culture. According to a recent poll by The New York Times and Siena University, a large majority of Americans now believe the country cannot mend its deep political rifts.

“We need leaders who will think about the people first,” said Wayne Dickens, 42, a minister and sports team chaplain for Southern Methodist University in Dallas. “Leaders are called to behave in a certain way, and our leaders haven’t done that.”

Barbara Rickel, 60, of Hayes, Kan., who works for a company coordinating shipments, said that lawmakers needed to find a way to work together, but that the system was not working. “I’m not saying Republicans are right or Democrats are right,” she said. “I’m saying our government structure is jacked up.”

Other Americans shrugged off the early days of the shutdown as typical of partisan gamesmanship and as a way to trim the government.

Mr. Talbert praised the president’s record and placed the blame for the shutdown squarely on Democrats, whom he accused of opposing Mr. Trump because they “hate him.”

“I wish they would come up with a better idea than just fighting him every step he goes,” said Mr. Talbert, a lifelong conservative who voted for Mr. Trump in all three of his campaigns.

The president, however, has lost the support of Elizabeth Maldonado, a 42-year-old security project manager in Dallas who once saw Mr. Trump as the businessman who might fix an ailing economy. Now, she said, she would not vote for him.

She grew disillusioned by Mr. Trump’s rhetoric and immigration enforcement tactics, she said. And she faults him for failing to unite Americans, or what she called the brotherhood. “We are one nation,” she said.

There is also a segment of Americans who, purposefully or not, tuned out the shutdown. Many weekend visitors to the National Mall in Washington said in interviews that they were only vaguely aware of the shutdown. One woman outside a grocery store in the Dorchester neighborhood of Boston said that she did not watch the news and did not even know there was a shutdown.

At Boston Logan International Airport on Saturday, Linda Dahl, 67, was preparing for a trip home to Seattle after returning from a cruise vacation along the New England coast. She said she was aware the shutdown had started but was intentionally not paying attention.

“Ignorance is bliss,” she said.

Darren Sands reported from Washington, Alessandro Marazzi Sassoon from Atlanta, Colleen Cronin from Boston; Krista Torralva from Dallas, Jenna Fisher from St. Louis and Abigail Geiger from St. Augustine, Fla.