Evelyn Chumbow was once a slave, but not in some distant country. She worked right here in the United States.
Chumbow, now 21, was brought to suburban Maryland in 1996 from her native Cameroon by Theresa Mubang. Mubang promised Chumbow's family that if 11-year-old Evelyn came to America, she would have the prospect of a bright future and a first-rate education, as she had been a top student in her native country.
Instead, after she arrived, Mubang enslaved the child in her home, forcing her to work long hours and depriving her of the education she was promised, and never paid her a dime.
In Chumbow's first-ever television interview, she recounted to ABC News how she survived her ordeal and triumphed over the sadistic woman who held her captive.
"When I didn't do what she wanted me to do … she would beat me up," Chumbow said. "And when she get tired of beating me up, she had like pretty long nails and she would scratch me with it, grab me by her nails."
Quite a difference from what she imagined when she watched "The Cosby Show" and "The Fresh Prince of Bel-Air" in Cameroon, and dreamed of becoming a lawyer in the United States. But after she arrived it soon became clear her dream would become a nightmare, as she got caught up in an underground trade that affects thousands of people across the country.
Government estimates say about 15,000 to 18,000 people enter the United States annually to work in deplorable conditions for little or no pay. These men, women and children are ensnared in global human trafficking -- a lucrative and thriving underground trade involving an estimated 800,000 people worldwide every year.
Chumbow is now free and is rebuilding her life while striving to help others, and she said the worst part of her treatment was how Mubang spoke to her.
"All the words that she would say to me would hurt more than the beatings -- like calling me dumb and dirty," she explained. "And that I was not smart and I would never make it, and if she would send me to school she wouldn't know what I would be doing in school."
She found herself asking "why is this happening to me" and looking longingly outside the window as other children boarded a school bus in the morning.
"I was crying. I was like, 'I wish that was me,'" she said. "Those times I would think about running away or just going back home."
"What I would say to the American people is that they have to realize that this happens all over the country, in the backs of restaurants, in the fields in Florida, in the timber industry in the north of New York. There's nowhere in America that it doesn't happen," said Melanie Orhant, Chumbow's former attorney and the managing attorney for the Break the Chain Campaign, an organization that helps trafficking survivors.
Assistant Attorney General Wan Kim, head of the Justice Department's Civil Rights Division, said money drives the thriving human trafficking industry, one of the most lucrative of the underground trades.
"When you ask yourself, how could a human being do this to another human being, there's no good answer to that. But one of the answers is, boy, they're making a lot of money or saving a lot of money by doing that," said Kim.
"We've had cases where people have been victimized and forced into domestic servitude for more then [a] decade," Kim explained. "Think about how much … a person could save if they didn't have to pay for house cleaning, for cooking for babysitting services for that period of time."
Some slaves are simply kidnapped and slipped across U.S. borders. Others -- too poor to pay off the transport fee of ruthless smugglers -- work for months to pay off the debt. Some are enticed by work or tourist visas, only to be forced to work for little or no pay.
Kim said some victims are "being lured to America with false promises of a good education, a good life in America and being forced to cook, to clean, to care for one's children, forbidden from leaving, often beaten, often sexually abused."
"We've had terrible cases of victimization in almost any category of human misery that you can imagine … working in the fields, working in homes, working in sweatshops, producing for garment factories and working in brothels.
"These are terrible, terrible, terrible cases of victimization, and the worst of it is, the victimization is ongoing," Kim explained. "It's not one time -- that would be bad enough. It is over and over and over again, sometimes for years."
Their captors control them with the threat of arrest or deportation, or as in the case of Chumbow, with beatings.
Victims of slavery often cannot speak English, and sometimes they cannot read or write -- factors that magnify their isolation. And with no friends or family nearby, for all intents and purposes -- they don't exist.
To escape their situations, many slaves eventually run away from their captors and find help through the dozens of support groups focused on ending human trafficking throughout the country. Alert law enforcement and neighbors also bring attention to suspicious situations.
A recent case involved a girl brought from Egypt to work seven days a week for a wealthy couple in Irvine, Calif. Federal prosecutors showed a home video at the couple's trial, showing the girl cleaning up after her masters' family while everyone else, including children who appeared to be about the same age as the Egyptian girl, enjoyed a birthday party.
In another case, two Milwaukee doctors were sentenced to four years in prison for enslaving a young Filipino woman for 19 years. She lived hidden in a basement storage room of the doctors' upscale home, allowed upstairs only to work as a servant.
"I think most Americans would be saddened and shocked to know about the extent of this problem," said Kim.
Once freed, the victims of slavery try to piece their lives back together. There are dozens of support groups around the country to help them get education, employment and counseling.
"These clients are not viewed as criminals, even if they are in the United States illegally. … They should be given rights as victims of a crime. The federal government should view them as victims of a crime. We certainly view them as victims of a crime," said Orhant.
"There are criminal laws that have been set out and created and have been passed to assist these individuals. There's immigration laws that have been created and established to assist these individuals and that's what we do," she continued.
Chumbow, now 21 and pursuing the American dream that was once unreachable, has a simple yet powerful message for others in these situations.
"Don't give up. Just think positive and keep your head up and it's hard and you feel lonely and empty like nobody cares but there is people that care," Chumbow said.
You can also learn more from the Department of Health and Human Services' Rescue & Restore Victims of Human Trafficking public awareness campaign.
If you have information about human trafficking in the United States, please contact the the Department of Health and Human Services' National Human Trafficking Resource Center or call this toll free number: 1-888-3737-888.