Every year, tens of thousands of young people scrape together money to obtain J-1 visas and travel to the United States, participating in a cultural exchange program that promises immersion in American life.

But many of them have suffered abuse and mistreatment at the hands of their American employers in a poorly regulated program that is ripe for exploitation, a New York Times investigation has found.

Some of the employers have forced visa workers to pack dog food on assembly lines in Iowa, hose out pig pens in Nebraska and pressure renters into signing leases in run-down apartment buildings in New York.

The Times spent months reviewing thousands of pages of legal records and regulatory documents and talking to labor lawyers, researchers and J-1 visa workers. The investigation focused on the New York region, which draws more of the workers than nearly anywhere else in the country, and on the visa holders who experts say are most susceptible to abuse: seasonal workers, interns and trainees.

Here are four takeaways from the investigation:

People on the J-1 visa were injured on the job after being sent to dangerous workplaces.

Dozens of visa workers from around the world came in recent years to Kurt Weiss Greenhouses on Long Island, one of the largest plant nurseries in the nation, where they helped grow, harvest and transport the millions of flowers and succulents the company ships to stores around the country.

But the visa workers were unaware of the company’s safety record — one fatal accident and more than 35 injuries were recorded there from 2014 to 2017 — and they were expecting advanced training, good pay and ample time off.

Instead, they worked up to 60-hour weeks for meager wages, doing grueling manual labor while their bosses threatened to have them deported if they did not work fast enough. One visa worker was sprayed with chemicals while working in the greenhouse without protective gear. Another had his hand mangled under a forklift.

A third visa worker from Serbia, Dino Cekic, was loading heavy planters of flowers onto a cart in 2018 when it crashed down on top of him, dislocating his shoulder. Weeks later, Kurt Weiss dismissed him from his job. He returned to Serbia, where he had to dip into his savings to pay for shoulder surgery.

“You get that beautiful story where it’s all sun and rainbows, but it’s really not,” said Mr. Cekic. “For me, it was a disaster.”

A representative of Kurt Weiss said that the company treated all visa workers with respect, and that most had positive experiences, but declined to answer questions about the company’s safety record.

Workers said that they were sexually harassed and cheated out of wages.

Other workers across New York described facing other kinds of workplace abuse.

Seven visa holders said they were choked, spanked or kissed against their will by their boss at a cafe called Marie Eiffel on Shelter Island.

Vannessa Chao Wan Yi, a student from Malaysia who worked at the cafe in 2022, said her boss, Françoise Lapostolle, groped her breasts and touched her anus through her pants, according to a lawsuit she and other workers filed in 2023.

A lawyer for Ms. Lapostolle, who goes by the name Marie Eiffel, said she denies the allegations and “is confident she will prevail.”

Other visa workers said that they were lured to office jobs and cheated out of wages.

When Lina Restrepo, a visa worker from Colombia, began at a Manhattan media firm called Skytop Strategies, her boss promised her $60,000 a year, training in social media and time off to see the city.

Instead, she said, she often worked 12-hour days, including on weekends, until the company stopped paying her and others entirely.

The chief executive of Skytop, Christopher Skroupa, had previously been sued by some of his American employees who accused him of fraud and deceptive business practices. He made excuses and promised the visa workers that the funds were coming, emails and interviews show.

But Ms. Restrepo went months without being paid and quit in May 2023, deeply in debt.

Mr. Skroupa declined to comment.

The State Department outsources most monitoring of the program to labor brokers known as sponsors.

The J-1 visa program was started at the height of the Cold War with the stated goal of fostering good will between the United States and other countries. It is run by the State Department, but that agency has outsourced responsibility for monitoring the program to dozens of nonprofit groups and for-profit companies.

Known as sponsors, the groups act as labor brokers and charge anywhere from $1,000 to more than $2,000 in fees to international applicants to help them with their visa paperwork and with finding jobs with American employers. The sponsors are supposed to vet those employers, but their bottom lines depend on maintaining good relationships with them.

In audits, the State Department has been faulted for poor oversight of the program and for allowing some J-1 holders to toil in jobs while receiving none of the promised training, education or cultural experiences.

A spokeswoman for the State Department said it “takes every case of alleged abuse seriously” and works with law enforcement and other organizations “to safeguard the health, safety and welfare of every exchange visitor.”

Sponsors and their representatives have played down or ignored workers’ complaints.

Sponsors are supposed to intervene when visa workers have problems with their jobs. But workers said that when they have complained about abusive working conditions, sponsors and their representatives have done little to help.

In 2016, Carolina Rodriguez pleaded with her sponsor for help when an architecture studio in Brooklyn refused to pay her the $2,400 monthly salary she was promised, records show. After she was fired from her job, she said her sponsor told her she had just weeks to line up employment elsewhere or would have to leave the country.

She ended up returning to Colombia, forfeiting about $2,000 in fees she had paid the sponsor to come to the United States. She later sued the architecture firm, Studioteka, for breach of contract and received a settlement. (Studioteka’s chief executive disputed Ms. Rodriguez’s account and said she had been fired for performance issues.)

Years later, other sponsors approved the same architecture studio to employ more visa workers.

Iryna Humenyuk arrived at Studioteka in 2019 after her sponsor, Intrax, signed off on the company. She said she soon found a toxic work environment where she was sexually harassed by an employee.

Studioteka’s chief executive, Vanessa Keith, said that she was unaware of the harassment and that most visa workers had positive experiences. Intrax said through a representative that it did not know about previous complaints about the company.

Ms. Humenyuk complained repeatedly to her college, which had helped her find the job. But when she asked whether the architecture firm would be barred from hiring more J-1 workers in the future, she never got a response.