Author John Steele Gordon says two factors contributed to the rise of the New South in the 20th century: desegregation and air conditioning.
"Those were the two main things," he said.
The combined social and technological advancements led to rapid development in the South. Soon people began moving there in search of work and to escape the harsh northern winters.
Air conditioning made the summer heat more tolerable in the South. It also sparked a surge in manufacturing. Prior to its invention in 1902, Southern states manufactured few goods beside textiles.
"The working floors were often just so incredibly hot that they were unendurable," Gordon said.
Air conditioning changed all that. It led to a boom in manufacturing. Plants sprung up across the South and migrant workers soon followed.
Not surprisingly, the South became increasingly influential in national politics as it continued to develop during the 1900s. In the Civil War Era, Gordon explained, the 11 confederate states had 128 electoral votes. Now, those same states have 160 votes.
The South also turned into a hotbed for conservative Republicans during the 1900s. It's easy to forget that the Deep South was one of the most consistent Democratic voting blocs in the first half of the century.
"They hated Republicans who they thought were responsible for the defeat of the South in the Civil War," Gordon said.
President Abraham Lincoln was a Republican.
Gordon says the flood of migrant workers and new businesses had little to do with the rise of the Republican Party across the South. The advent of air conditioning didn't cause the change in voting behavior in states like Georgia or Alabama.
Gordon points out that southern voters have always been conservative, even the ones who once voted for so-called Dixiecrats, or southern Democrats. It just took them a while to adjust their voting habits to reflect their beliefs.
"They started voting Republican 100 years after the Civil War," Gordon said. "After 100 years, you finally get over it."