Helper, a native of North Carolina, argued in his book that slavery was bad for the economic prospects of poor white Southerners.
But demand far outstripped supply, and the price of slaves rose inexorably, placing ownership outside the reach of poorer Southerners.
The rural blues of poor black Southerners and the jazz of black urbanites were among the earliest styles of American popular music.
"But I still do believe that there are useful things to say about Elvis Presley, including what his own ordinariness as a poor Southerner says about 20th-century hero-making."
In the Depression, poor Southerners moved north; as the Industrial Belt rusted, tens of millions moved to the Sun Belt.
During the Civil War, Union soldiers were amazed to see poor Southerners without any stake in the slavery system defending it in suicidal charges.
The report, "Miles to Go," was issued yesterday by the Southern Education Foundation, an Atlanta advocacy group that works to improve educational opportunities for black and poor Southerners.
Like "Ray," "Walk the Line" tells the tale of a poor Southerner, born in the early years of the Great Depression, whose childhood was marked by the death of a beloved brother.
Some reviews lamented the use of poor white Southerners, and one-dimensional black victims, and Granville Hicks labeled the book "melodramatic and contrived".
However, 45% of all poor Southerners lived in the 3 border provinces.