In 1992, NAFTA was signed with the promise that it would create such great jobs in Mexico that Mexicans wouldn't want to illegally immigrate to the U.S. But in the two decades since, the number of people living illegally has nearly quadrupled. - 

Twenty years ago, in 1992, the North American Free Trade Agreement was signed, establishing the world's largest free trade zone. NAFTA promised that it would create such great jobs in Mexico that Mexicans wouldn't need to illegally immigrate here. But in the two decades since, the number of people living here illegally has nearly quadrupled.

Omar's story starts with the story of his father -- who moved from a tiny pueblo to the northern Mexican state of Sonora in the early 1980s with only a third grade education, determined to make it.

"He was like - I can do it. I can handle it," says Omar.

And Omar -- who asked that we only use his first name -- says his dad did make it. He started a business making meals for workers at a new car manufacturing plant in the city.

But a decade later, when it was Omar's turn to enter the labor force, Mexico had changed -- and NAFTA was a big reason why. The trade agreement lifted tariffs that had been on U.S. commodities like wheat and corn, making them suddenly very cheap in Mexico. The local food suppliers Omar's dad had been using for years couldn't compete.

And so, neither could Omar's dad. "So he couldn't make it," says Omar. And a different, more industrialized food-company took over. Omar says, "Instead of using things like eggs, they used powdered eggs, powdered milk, powder potatoes."

Omar's family lost their house, and Omar quit school at 14 to work full time. He found that even for entry level jobs a high school diploma mattered, and English mattered -- two things which Omar's dad hadn't had to worry about in pre-NAFTA Mexico.

"I had a lot of advantages over him, and it was like 1,000 times harder for me," says Omar.

It seemed to Omar that the only place where it was still feasible to make it on hard work alone was the United States, legal documentation or not. So in 2002,  he moved to Arizona and started working, illegally. That same year researchers estimate that about 600,000 other Mexican immigrants also came to the U.S. -- roughly double the number who came in 1991. Originally NAFTA had promised to create enough new manufacturing jobs in the cities to absorb all the people who now couldn't compete with U.S. agribusiness.

But economic-sociologist Kathleen Schwartzman says that's not what happened, "and that's one of the sources of the migratory push, because there wasn't an adequate match."

After 10 years in the states, Omar is finally opening his own business -- a house painting company. He's raising his son to believe in the same U.S. he found in the early 2000s, just as his father raised him to believe in the Mexico of the 1980s. But since Omar knows the economic landscapes of places tend to change, he has a back-up plan for his son: "Well, I will encourage him to learn some Chinese, by the way. You never know."