Story highlights Marieme escaped from Mauritania, a West African country where slavery is common

Experts say 10% to 20% of Mauritanians live in slavery today

Marieme was smuggled to the United States in the hull of a cargo ship

When she fled she had to leave her children behind, hoping they would be rescued, too

On a cul-de-sac behind a strip mall in an anonymous neighborhood of this Midwestern city is an incredible story of escape from slavery.

Marieme's neighbors don't know her history. She mostly keeps to herself in her modest stucco house, 4,000 miles from her native Mauritania. Her six children know their mother's story well. She rescued them from slavery, too.

They are living a life they never could have hoped for in Mauritania, where an estimated 10% to 20% of people are enslaved.

The horrors Marieme endured as a slave in West Africa still dominate her dreams and flood her eyes at unexpected moments. In her first attempt to escape, she ran for two days and two nights through the Sahara Desert, barefoot, only to arrive at the home of another slave owner, who returned her to her master.

"They did everything to keep me from running away. See, they branded me so I wouldn't walk any more," she says in French, lifting up her fuchsia dress to show large patches of scar tissue on her calves and knees, caused by a metal poker. "But it's God that helped me."

A CNN reporter and videographer visited Marieme, 55, shortly after traveling to Mauritania to document slavery in a place where it is arguably more prevalent and more ingrained than anywhere else in the world. After witnessing the bleak reality there, we wanted to hear from someone who had risen up against the odds -- who had escaped not only her master but her country.

How had she done it? Who helped her along the way? And how did she end up in Ohio? We hoped to uncover a sort of formula for freedom. Perhaps parts of it could be replicated by hundreds of thousands of others.

We wanted to know: Could an escaped slave truly be free?

In Mauritania, we met men and women who had escaped slavery only to meet new forms of misery. They had no training for jobs, no possessions, no concept of ownership. Life was not instantly better just because they were free.

Several slaves, freed slaves and abolitionists in Mauritania told us the biggest barrier to freedom is psychological. Slaves usually aren't physically chained to their masters' lands, but they are taught to believe that they belong there -- that they're less than human, and it's their place to serve those with lighter skin.

We wondered if Marieme had managed in her new world to shake those mental shackles.

Or if slavery had followed her family all the way to Ohio.

The slave and the awakening

Marieme was 3 or 4 when she started working for her master -- serving food, cleaning dishes and taking care of his children.

"I had to walk kilometers and kilometers to get water," said Marieme, whose real name is not being used because she has been threatened for sharing her story and because she still has family in West Africa. "There was no gas for cooking. We had to gather wood to cook with. ... It wasn't easy."

They lived in southern Mauritania in the Sahel, the arid region that divides the jungles of sub-Saharan Africa from the Sahara Desert. She never knew it as a young girl, but not far to the south was the river that separates Mauritania from Senegal, and slavery from freedom.

Her mother, father and siblings lived in a building near the master's family and worked long hours for no pay. When she was about 12, her brothers and sisters -- five in all -- disappeared, one by one. She never knew where they went, and her mother couldn't answer questions about what had happened. Now, Marieme figures the master gave them away as gifts.

He also started sexually abusing her around that time, Marieme said in an affidavit filed in her asylum application after she arrived in the United States.

"Beginning when I was 12, the chief of the family raped me many times," she said, according to the court document. "I remember that the first time he raped me, when I was 12, I bled. I showed my mother what had happened, and my mother sobbed and cried.

"She was terribly upset for me, and she knew that she could do nothing to help me. She told me that the same thing had happened to her."

Slaves in Mauritania often do not have identity papers and are not allowed to go to school. But Marieme was given a secret education.

When the master wasn't around, his son took her into the family's study and taught her to read and write. He also gave her French lessons; it became their code language. No one else in the family spoke it.

The master's son was himself well-educated. He told Marieme about life outside the farm -- about a world without slavery. He said she should be free; that she and her family should not have to work in abusive conditions without pay.

This system, he said, robbed them of their human dignity.

Awakened to those ideas, Marieme would never let them go.

The run

Soon, she plotted her escape.

"I had told my mother that one day I would be free," Marieme recalled. "She told me, 'If you do that, you are going to die because they are going to kill you.'"

Her mother begged Marieme, her only remaining child, not to flee. Besides, where would she go?

"There were those who didn't want to leave," Marieme said, echoing sentiments we heard from slaves and recently escaped slaves in Mauritania. "They had no idea where to go. They were scared. It was a risk. You have to look for places to sleep, places to eat.

"You have to have a lot of courage for something like this."

Marieme found motivation in the stories she heard about a world beyond her own -- one where she could choose what to do with her days. She would do whatever it took to escape.

The river separating Mauritania from Senegal was only 2 or 3 miles south of the camp where she lived. She didn't know that, though, and one night she ran north, without shoes or supplies. She ran and ran -- as fast and as far as she could -- through the heart of the Mauritanian desert.

After two days, she sought help at a house.

It was owned by another slave master.

He forcibly returned Marieme to her owner, whose punishment nearly ended her life.

"They bound my wrists and ankles and tied me to a date tree in the middle of the family compound, and left me there for a week," she told attorneys when she applied for asylum. "He beat me many times during that week. He cut my wrists with a razor, so that I bled terribly. There was so much blood that he had me brought to a doctor, who sewed up the wounds. As soon as I returned, the chief of the family tied me up again. He refused me food while I was tied up. A few times at night, while everyone was sleeping, my mother snuck me a little bit of food. She had to feed me, because my hands were bound."

The message was clear:

If you run again, I'll kill you.

Across the river

Marieme was not deterred.

The death of her parents -- and the destiny of her children -- prompted her second escape attempt.

In 1996, her father lost some of his master's camels in the desert. He was quite old at the time, Marieme told authorities, but that would not save him. He was severely beaten. The camels later returned, but Marieme's father died two months later, she said.

The next year, Marieme's mother passed away, too.

Marieme knew she had to go.

"I couldn't stay there," she said. "I really wanted to leave -- to get my children out of there. I made my decision."

Another slave came up with the plan.

He stole money in small chunks from the master, she said, and used the cash to hire a smuggler who would take Marieme on a boat across the river to Senegal, and then transport her from there to Dakar, that country's capital city, some 200 miles away.

The catch: Marieme would have to leave her children behind.

One or two could fit in the small, wooden boat, her helper said, but there was no way she could travel with all six. Marieme maintained her resolve. She spoke with her oldest daughter, telling her she would come back for her and all the rest after she made it to freedom.

"I told her I was leaving and she needed to watch out for the others. She cried and cried, but I told her it would be OK."

Don't forget me, she said.

One night, the slave woke Marieme.

"Get up, get up," he whispered. It was now or never.

Marieme grabbed some clothes and followed him toward the Senegal River. When she arrived at its banks, she stood in awe. She'd never seen a body of water before -- never smelled the musky, sweet smell of a river.

A small, wooden boat took Marieme across the water to freedom.

"When I arrived, the sun was just coming up."

Across the ocean

When Marieme arrived in Dakar, Senegal, she knew little about the world outside the small, desert village she had escaped. She'd heard people talk about France, the country that colonized Mauritania. But she'd never heard of the United States.

What she did know was this: Senegal did not feel safe -- nor would any part of Africa. She woke up every morning a free woman. But she feared her master could appear at any moment.

If he captured her a second time, she was certain she would be killed.

Marieme befriended a man in Senegal who she said helped run an Underground Railroad of sorts, smuggling escaped slaves from Mauritania to safer places.

She lived with him for two years in a safe house full of refugees. There, she experienced something only a free person could: She worked for pay.

"I worked there and each month, he paid me," she said. "I cooked and cleaned and he paid me. For me, it was great because I had never been paid before. Even a dollar and I was happy. I was proud."

The man who ran the safe house came to Marieme one day and said something incredible:

Tonight, you will go on a boat to America.

Marieme had never seen a boat before the night she floated on a wooden canoe across the Senegal River. This time, she would escape on a cargo ship. And America? It was the first time she'd heard of this faraway place.

She would be safe there, the man said -- far from anyone who could enslave her.

The mother thought of her children, still enslaved by the master.

And again, she knew she had to go.

This place called America, she thought -- it would be a safe place for them.

Another voyage to freedom

Helping care for her siblings back in Mauritania, Marieme's daughter Zeina, who CNN also is not identifying by her real name, knew nothing of what had happened to her mother. She was gone -- and that was a good thing, Zeina figured.

The more days that passed, the more Zeina was sure her mom had succeeded -- that she was free and living in some other land.

The distance was made easier, in a strange way, she said, because Marieme was often absent when living with them in slavery: She was forced to put the master's kids first.

While her family was wondering about her safety, Marieme was packed between crates in the hull of a cargo ship, en route to America. There was nothing to do but sleep, stand and eat the food brought by a ship worker who was in on the plot. The journey lasted nearly a month, but to Marieme it flew by.

"For me, it was a day," she said.

On that journey, Marieme realized -- for the first time with certainty -- that she was free.

Little Mauritania

On December 24, 1999, the ship carrying Marieme landed in Baltimore, where another smuggler passed the refugee into a safe house.

Soon she made her way to the Bronx, New York, where many Mauritanians live. She stayed in the region for a few years, braiding hair and cooking for a living before she heard through a friend that some Mauritanians had gone to Ohio. The rent was cheaper, the friend said, and there were higher-paying jobs in manufacturing.

When Marieme arrived in Cincinnati in 2003, she took a job at Krispy Kreme. She sent as much of her $7-per-hour salary as she could back to Senegal, where the smugglers who helped her were working on another plan.

They would rescue her six children, all at once.

They were brought along the same path their mother had followed. Several stayed in Senegal for years, waiting to enter the United States legally. By that time, Marieme had gained her right to be in America, too.

In 2001, Marieme was granted asylum in the U.S. as a political refugee, she said. In June 2010, she became a citizen of the United States, according to records she provided.

One by one, her children joined her in Ohio.

Her daughter Zeina came by plane.

She calls it one of the most frightening experiences of her life.

'Maybe one day'

Marieme and her children live simple but extraordinary lives in Ohio.

On a recent night, Marieme, Zeina, a son and a granddaughter sat on a mat on the living room floor and shared a meal of cooked beef and salad, which they ate with their hands, as is customary in Mauritania and some other parts of Africa.

Spices thickened the air and the smell of incense clung to everything. Marieme's granddaughter batted at a toy dog. A large television blared the words of an "Entertainment Tonight" host, who was talking about Madonna's Super Bowl half-time performance. When the host mentioned the performer's age, 53, Marieme expressed shock and delight.

She looks so strong and young, Marieme said.

After coming from such a small, harsh place in the desert, Marieme and Zeina are completely fascinated by how big the world really is.

They spend much of their time watching television, trying to soak up all this diversity through the satellite dishes on the roof of their home in north Cincinnati. Earlier in the day, Marieme had watched news from ABC, CNN, Al Jazeera, the BBC and a Senegalese satellite network.

Zeina is in college, studying business, and she hopes to work in the travel industry. She wants to see the world and learn about other cultures. Her first trip would be to Singapore, she said, because she heard people there are nice.

What is most dear to Marieme is her children's success. All of them are enrolled in school, five in the United States and one in Senegal, where he is trying to get clearance to come to the U.S.

In a generation or two, her family's chains of slavery will be completely broken.

"They go to school so they can be senators, they can be in Congress, who knows," Marieme said. "Maybe I can't do it -- but they can."

Her son in high school barely remembers Mauritania. He doesn't speak Mauritanian languages well, which is just fine by Marieme. He's in America now, she said. Those other things aren't important. She proudly displays a picture of his soccer team in the living room.

Her granddaughter represents the future.

Born outside Mauritania, she is the first generation of Marieme's family not to be scarred by slavery. Marieme spends much of her time sitting on the floor with the child, cooing, smiling and shaking toys. The girl's eyes light up when she sees her grandmother behaving in such silly ways.

All of this brings Marieme unimaginable joy.

She is heartbroken, however, about the people she left behind in West Africa.

"It's not normal, what goes on there," she said. "Maybe one day Mauritanian law will change all of that. Like Lincoln did here. Abraham did it here, why can't they do it there? It can't continue like this. It's not normal. For generations and generations."

In fact, Mauritania passed a law criminalizing slavery in 2007. Only one case has been prosecuted successfully.

Marieme's daughter sees little hope for slaves in Mauritania.

"I don't think it will ever change. It's been hundreds of years" that they've been enslaving people, Zeina said. "Why would they stop? They don't know there's a world somewhere where people don't own slaves."

But Marieme is sure things can and will be different -- eventually.

"If my mother were alive and you told her I had come to the United States with my children, she would say, 'No, that's not possible.'

"But you see how things have changed for me. So you see, I think it will all change one day" in Mauritania. "I just don't know when. But it's possible."

Four thousand miles from her homeland, Marieme often has trouble sleeping. The demons of the past come back to haunt her.

"I have terrible nightmares about the terrible things I lived through in Mauritania," she said in her sworn testimony. "Whenever I see a older white man with a long beard, I feel horribly afraid -- because this is what the master of my family looks like."

When she does sleep through the night, she dreams about having the resources and the courage to return to Mauritania.

In those dreams, she goes from house to house and sets all the slaves free.