(NBC News) - Just how much does the U.S. rely on immigrants? Americans may be about to find out.

Spread on social media and messaging apps, the informal campaign aims to make Thursday a "day without immigrants."

Foreign-born residents of the U.S., whether they are with or without the proper documents, are being asked to stay home from work — and to refrain from shopping, as well.

Hankering for a burrito this lunchtime? Good luck to you. Hoping your hotel room will get made up, fresh towels and all? Might not happen.

Not to mention the hard work of doctors, lawyers, academics and scientists who were born abroad.

And what about the president of the United States? He might just find himself wifeless, as one tweet pointed out, considering that his spouse, Melania, was born in Slovenia.

No one is sure how the day got started. But it's all over social media with #DayWithoutImmigrants trending on Twitter across the U.S. early Thursday.

Some restaurant chains have announced plans to close, amid fears that many employees will not show up for work.

Celebrity chef José Andrés, who was born in Spain, said he would close most of his eateries Thursday to observe the day.

And Saru Jayaraman, co-founder of Restaurant Opportunities Centers United, an advocacy group for restaurant workers, issued a statement supporting the one-day boycott.

"Immigrants are the lifeblood of the restaurant industry," Jayaraman said. "At ROC, we honor the major contributions of immigrants in the restaurant industry — an industry that employs perhaps more immigrants than any other in the U.S. We applaud and support restaurants and workers who, by participating the the Day Without Immigrants, affirm the dignity of workers. Furthermore, we call on all Americans to recognize the influence and importance of immigrants in our communities, economy and daily lives."

Other social media users, however, suggested that Thursday would be an excellent time for people born in the United States to reclaim the jobs they say that immigrants have taken away.

This is not the first time that advocates for immigrants have tried to point out what they say is their value to the American economy. Advocates say immigrants often do work that other residents of the U.S. do not want to do.

Cheap lettuce, for example, is said by supporters of immigrants to be available because of migrant farm workers. Chicken is affordable in super markets, advocates contend, because Mexicans and other immigrants work in chicken plants, sometimes in undesirable conditions.

This has been a theme advanced for many years by supporters of immigrants in the U.S., whether documented or undocumented. They contribute to the economy rather than harming it, advocates say.

This issue, of course, is not new. A decade ago, the American musician Tom Russell wrote a song questioning plans to build a wall along the the U.S.-Mexican border to keep immigrants out.

"If Uncle Sam sends the illegals home," the song asks, "who's gonna build the wall?"