Texas
Starr County is "as close to a developing county as you can get and still be in the U.S."
People live in clusters of trailers and homes with no electricity or plumbing, said Cynthia Osbourne, director of the Child and Family Research Partnership at the University of Texas-Austin. Dirt roads abound in this county, which borders Mexico.
Starr has none of the oil and gas resources that fuel the Texas economy. It's mainly rural, depending on agriculture. And it has the lowest median income in the state.
Some 43.6% of residents live in poverty and unemployment is at 14.2%, far higher than the state's 17.9% poverty rate and 5.1% unemployment rate. Fewer than half have high school degrees.
Some 96% of its residents are Latino, many of whom come from families who have lived in Texas for years. Only 31% are foreign born.
A world away is Rockwall County, which serves as a suburb of the Dallas-Fort Worth metro area. Residents are employed in well-paying jobs, including high-tech and engineering, said Steve Murdock, sociology professor at Rice University. Unemployment is a low 4.9%, and only 6.7% of the population are below the poverty line.
Between 2010 and 2012, the county had the second-fastest job growth in the nation -- 13%, CNNMoney found. Among the industries expanding or relocating there were aerospace, logistics, defense and manufacturing firms.
