That is because the underside of a newcomer's American dream is often the breakup of a marriage and family back home. Tens of thousands of married immigrants tearfully kiss their spouses and children farewell and sneak across borders or fly in on tourist visas they will probably let lapse, to secure gritty jobs with wages that go much further back home.

Stays that some thought would last a year or two stretch to 5 and 10 years or longer as illegal immigrants come to realize that making the journey home might mean never returning to the United States. After a time, their spouses and family back home become strangers, or they succumb to loneliness and meet other lovers. Some seek out citizens of the opposite sex for sham marriages that they hope will lead to the brass ring of legal residency. And then there are the immigrants, legal or not, who end up in legitimate marriages here that cannot withstand the isolation and bewilderment that come with being in an unfamiliar country.

All of these people provide more than enough business for the dozen or more divorce lawyers or paralegals along the neighborhood's clamorous, el-shadowed thoroughfare that seems to have been patched together to cater to immigrant needs.

"The human race is a very optimistic race," said Jesus J. Peña, one of the busiest lawyers along the strip, whose office there handles 10 divorces a week. "Everyone thinks they come to the United States and will make enough money to build a house and educate their kids and then they will go back," he said. "The first year they don't make enough money. The second year they don't make enough money. After 15 years, they're still not making enough money and they're still here. You may find a girlfriend, and that's when you need a divorce."

A compact man with dark plush eyebrows and silver sideburns, Mr. Peña has seen so many quirky divorce cases that he has come to adopt a world-weary stance toward the parade of human schemes and illusions. He sighs at how often men with wives and children come here illegally, risking breaking up their families back home.

Mr. Peña, 67, who arrived here alone as a 24-year-old from Castro's Cuba, runs four offices in New York and New Jersey that employ 25 lawyers in all; he estimates that his offices represent a total of 25,000 clients in divorce, deportation, malpractice, accident and criminal cases. He works out of the second floor of a squat two-story building that fairly touches the elevated train on Roosevelt Avenue. A blue awning trumpeting his name and who you will find in his office - "Abogados" - wraps around the roof. For divorces, he charges $900.

Rodolfo Rodriguez, a 37-year-old illegal Mexican immigrant who walked into Mr. Peña's office three months ago, is in many ways a typical divorce client. Five years ago, Mr. Rodriguez was earning $129 a week at a Nestlé yogurt plant in the Tlaxcala area east of Mexico City. He hugged his wife and six children goodbye and, with the help of a smuggler to whom he paid $1,500, he walked across the border and made his way to New York.

He settled in the Bronx, and found work as a packer at a Manhattan meat market, a job that pays $400 a week. Half of his earnings go to his family in Tlaxcala. Last year his wife divorced him in Tlaxcala on the grounds of abandonment.

"I was depressed, because when I came to this country, I thought I was doing the right thing by helping my family financially," said Mr. Rodriguez, a round-faced man with a black mustache and doleful brown eyes. He now has a Puerto Rican girlfriend but still sends money home.

Although it is possible for immigrants to get a divorce in New York State, some who come into the country choose to get their divorces in foreign courts. Fanny Villacres, a licensed lawyer in Ecuador and a paralegal on 37th Avenue in Jackson Heights, represents the Ecuadorean public defender's office here in a variety of matters, including divorce. She said that Ecuadorean law allows for a divorcio tacito, or an implicit divorce, for cases where the spouses have lived apart for three years.

The demand for divorce is often so urgent that Ms. Villacres and other lawyers tell of a shadowy phenomenon known as divorcio al vapor - where a man eager to shed a wife files for divorce here and sends a summons to his native country that is delivered to an address where his wife does not live. The claim is made that the spouse could not be located.

In some cases, the need for a quick divorce stems from the prospect of marrying a citizen, but this can involve deception, too. Ms. Villacres said she once had two Ecuadorean clients - brothers who were both bakery workers - who married the same Puerto Rican woman hoping to get green cards. They each paid the woman $7,000, but she vanished.

"I had to do divorces for both of them," she said. "It was sad, because they were young people."

But if her client is illegally here, even marrying an American citizen does not mean automatic access to a green card, she said. "You can do it, but you get nothing even if you marry the daughter of Mr. Bush," she said. Nevertheless, other lawyers like Mr. Peña said that as a practical matter they have found that immigration investigators seldom bother illegal immigrants who have American spouses and stay out of trouble.

For those immigrants who do marry here, and forge relationships that do not solely exist on paper, long-distance separation is not an issue. But the pressures of immigration - the vulnerability of a spouse who is not a citizen, the isolation from family - can doom a relationship. In some cases, the breakups are accompanied by violent abuse.

Dorchen A. Leidholdt, director of the legal center at Sanctuary for Families, a citywide organization that provides shelter and other services for female victims, said 85 percent of her clients were immigrants. Because of their uncertain status, they often endure beatings or sexual humiliation, she said.

Du-Juan Zhang, 24, from Guangdong Province, came here in May 2005 on a fiancé visa to marry a Queens dentist, an American citizen who had met her on trips to China. It was on their wedding night in June that he first hit her, she said. Ms. Zhang, who used a nickname as her first name to disguise her identity, said her husband kept her from immersing herself in American culture. He would not tell her how to ride the subway or give her money for shopping. When she asked to take English classes, he accused her of seeking to meet other men. When she suggested that she work in his clinic, he hurled a heavy backpack at her.

"I was really scared," said Ms. Zhang, who is staying at a battered women's shelter. "My husband is rich, and he's a citizen of America. I'm an immigrant from China. I don't have any money. I don't have any relatives here."

In mid-July, she said, he punched her in the stomach with a closed fist and swatted her with a shoe. In pain, she had a friend call the police, who took her to a hospital and arrested her husband. He now faces prosecution in Queens. But Ms. Zhang is still worried because she is here alone and now is illegal to boot, because her visa has expired and her husband has refused to file the paperwork that would give her a conditional green card as his spouse. However, Ms. Leidholdt is petitioning to get Ms. Zhang residency as a battered woman who made a good-faith marriage.

Immigration has left a bitter taste for those who have lost families. Mr. Rodriguez, the Mexican meat packer, said he would advise countrymen to stay home.

"If you have something valuable such as a family, I would tell them not to come," he said.