PHILADELPHIA — The heart of Philadelphia's Italian Market was uncommonly quiet. Fine restaurants in New York, San Francisco and the nation's capital closed for the day. Grocery stores, food trucks, coffee shops, diners and taco joints in places like Chicago, Los Angeles and Boston shut down.

Immigrants around the U.S. stayed home from work and school Thursday to demonstrate how important they are to America's economy and way of life, and many businesses closed in solidarity, in a nationwide protest called A Day Without Immigrants.

The boycott was aimed squarely at President Donald Trump's efforts to step up deportations, build a wall at the Mexican border and close the nation's doors to many travelers. Organizers said they expected thousands to participate or otherwise show support.

"I fear every day whether I am going to make it back home. I don't know if my mom will make it home," said Hessel Duarte, a 17-year-old native of Honduras who lives in Austin, Texas, with his family and skipped class at his high school to take part in one of several rallies held around the U.S. as part of A Day Without Immigrants. Duarte said he arrived in the U.S. at 5 to escape gang violence.

The protest even reached into the U.S. Capitol, where a Senate coffee shop was among the eateries that were closed as employees did not show up at work.

Organizers appealed to immigrants from all walks of life to take part, but the effects were felt most strongly in the restaurant industry, which has long been a first step up the economic ladder for newcomers to America with its many jobs for cooks, dishwashers and servers.

Expensive restaurants and fast-food joints alike closed across the country, some perhaps because they had no choice, others because of what they said was sympathy for their immigrant employees. Sushi bars, Brazilian steakhouses, Mexican eateries and Thai and Italian restaurants all turned away lunchtime customers.

"The really important dynamic to note is this is not antagonistic, employee-against-employer," said Janet Murguia, president of the Hispanic rights group National Council of La Raza. "This is employers and workers standing together, not in conflict."

She added: "Businesses cannot function without immigrant workers today."

At a White House news conference held as the lunch-hour protests unfolded, Trump boasted of his border security measures and immigration arrests of hundreds of people in the past week, saying, "We are saving lives every single day."

Since the end of 2007, the number of foreign-born workers employed in the U.S. has climbed by nearly 3.1 million to 25.9 million; they account for 56 percent of the increase in U.S. employment over that period, according to the Labor Department.

Roughly 12 million people are employed in the restaurant industry, and immigrants make up the majority — up to 70 percent in places like New York and Chicago, according to the Restaurant Opportunities Centers United, which works to improve working conditions. An estimated 1.3 million in the industry are immigrants in the U.S. illegally, the group said.

The construction industry, which likewise employs large numbers of immigrants, also felt the effects of Thursday's protest.

Shea Frederick, who owns a small construction company in Baltimore, showed up at 7 a.m. at a home he is renovating and found that he was all alone, with a load of drywall ready for install. He soon understood why: His crew, five immigrants, called to say they weren't coming to work. They were joining the protests.

"I had an entire day of full work," he said. "I have inspectors lined up to inspect the place, and now they're thrown off, and you do it the day before the weekend and it pushes things off even more. It sucks, but it's understandable."

Frederick said that while he fundamentally agrees with the action, and appreciates why his crew felt the need to participate, he feels his business is being made to suffer as a result of the president's policies.

"It's hurting the wrong people," he said. "A gigantic part of this state didn't vote this person in, and we're paying for his terrible decisions."

There were no immediate estimates of how many students stayed home in various cities. Many student absences may not be excused, and some people who skipped work will lose a day's pay or perhaps even their jobs. But organizers and participants argued the cause was worth it.

Marcela Ardaya-Vargas, who is from Bolivia and now lives in Falls Church, Va., pulled her son out of school to take him to a march in Washington.

"When he asked why he wasn't going to school, I told him because today he was going to learn about immigration," she said, adding: "Our job as citizens is to unite with our brothers and sisters."

Carmen Solis, a Mexico-born U.S. citizen, took the day off from work as a project manager and brought her two children to a rally in Chicago.

"I feel like our community is going to be racially profiled and harassed," she said of Trump's immigration policies. "It's very upsetting. People like to take out their anger on the immigrants, but employers are making profits off of them. "

On Ninth Street in South Philadelphia's Italian Market, it was so quiet in the morning that Rani Vasudeva thought it might be Monday, when many of the businesses on the normally bustling stretch are closed.

Produce stands and other stalls along "Calle Nueve" — as Ninth Street is more commonly known for its abundance of Mexican-owned businesses — stood empty, leaving customers to look elsewhere for fresh meat, bread, fruits and vegetables.

"It's actually very sad," said Vasudeva, a 38-year-old professor at Temple University. "You realize the impact the immigrant community has. We need each other for our daily lives."

In New Orleans' Mid-City neighborhood, whose Latino population swelled after the damage wrought by Hurricane Katrina in 2005 created lots of jobs for construction workers, the Ideal Market was closed.

The place is usually busy at midday with people lining up at the steam tables for hot lunches or picking from an array of fresh Central American vegetables and fruits.

In Chicago, Pete's Fresh Market closed five of its 12 grocery stores and assured employees they would not be penalized for skipping the day, according to owner Vanessa Dremonas, whose Greek-immigrant father started the company.

"It's in his DNA to help immigrants," she said. "We've supported immigrants from the beginning."

Among the well-known establishments that closed in solidarity were three of acclaimed chef Silvana Salcido Esparza's restaurants in Phoenix; Michelin star RASA in San Francisco; and Washington's Oyamel and Jaleo, run by chef Jose Andres.

Tony and Marie Caschera, both 66, who were visiting Washington from Halfmoon, New York, thought a tapas restaurant looked interesting for lunch, but then realized the lights were off and the place was closed.

"I'm in support of what they're trying to say," said Marie Caschera, a registered Democrat, adding that immigrants are "fearful for their communities."

Her husband, a registered Republican whose family immigrated from Italy before World War II, said he supports legal immigration, but added: "I don't like illegal aliens here."