South Georgia's Telfair County (population: 13,355) is the poorest county in the state and one of the poorest counties in the country, according to five years of census data analyzed by 24/7 Wall St.

"Telfair County is the poorest in Georgia as well as poorer than all but nine of the other poorest counties reviewed," wrote Thomas C. Frohlich. "Over the five years through 2013, a typical household in Telfair County earned $26,634, nearly half the national five-year median household income of $53,046."

Frohlich's data comes from estimated median annual household incomes from 2009 through 2013 from the U.S. Census Bureau's American Community Survey, as well as additional data on education and employment from the Census Buruea and the Bureau of Labor Statistics. One note: the ACS considers inmates as "living" in their prisons; and Telfair is home to a state prison, so that population may dilute the median income and unemployment numbers.

Telfair County was included in an AJC investigation into the statewide crisis afflicting regional hospitals. (Telfair Regional closed in 2008.)

Telfair isn't alone -- a few common characteristics link the poorest counties in each state.

"The population of 24 of these poorest counties was predominantly rural. Eight had 100 (percent) rural populations. ... In the five years through 2013, the percentage of adults who had attained at least a bachelor's degree was below the comparable national figure of 28.8 (percent) in 45 of the 50 counties," Frohlich wrote.

The nation's poorest county by median annual household income was a little further north: McCreary County in Kentucky, with an income of $20,972.