It's possible to immigrate legally to the United States, but it's not easy and can take decades.
To move here legally, a foreigner must be sponsored by a relative already living in America or an employer, a local attorney said.
But depending on the category, the waiting time can be between three and 22 years, due to limits set by Congress, said Robert Divine, an attorney and chairman of the Immigration Group of Baker, Donelson, Bearman, Caldwell & Berkowitz.
"The way to get in line is through family or employment sponsorship," said Divine, who served as acting director of U.S. Citizenship and Immigration Services, a component of the Department of Homeland Security.
"If you don't have anyone who is legal who is connected to you in the right way, then you can't get in the line," he said. "[And] it's pretty hard to find an employer in the United States who wants to go through the process of sponsoring you if you are outside the United States and you are not going to be able to be here for five to 10 years."
The number of immigrants living in the United States - legal and illegal - has reached levels never seen before. In 2009 there were 38.5 million immigrants, the largest number in the nation's history.
Their share of the American population, 12.5 percent, is approaching levels not witnessed since the height of the industrial era, according to a Brookings Institution report.
Immigrants now account for one in seven U.S. residents and almost one in six workers.
Although the recession and improved conditions in the immigrants' home countries have slowed immigration slightly, there still are about 11 million illegal immigrants in the United States.
Illegal immigrants can be a burden to American communities, and have hurt the job prospects of other low-skill, low-wage workers, opponents say.
"It has lowered our wages," said D.A. King, president of Georgia's Dustin Inman Society, a group opposed to illegal immigration. "Nothing good has ever come from illegal immigration."
Some illegal immigrants, like many of the Guatemalans coming here, tend to be less educated, less proficient in English and have lower incomes.
"For a lot of the Guatemalan immigrants, they come to the United States, they work, but their incomes are so low they can't support their children so the taxpayer steps in and provides health care, free school lunch, food stamps, that sort of thing," said Steven Camarota, director of research at the Center for Immigration Studies, an organization that seeks stricter controls on immigration.
And because illegal immigrants in general earn little money, their tax payments and contributions are going to be modest as well, he added.
Illegal immigrants still pay into Social Security and Medicare, he said. But they don't spend a lot of money and therefore pay less in sales tax, and they rent low-income properties where the landowner's property tax is low.
"So what often happens is that you get a real strain on something like public schools and hospitals," Camarota said.