
Chris E. answered 10/10/19
History and Writing Tutor with J.D. & M.A.
There were a number of reasons.
For one, an entire generation of Southern men were either killed or wounded in the Civil War which depleted the workforce and its capabilities. Two, the Southern economy was based on farming and agriculture, so when the slaves were freed, there was a drastic decline in available workers. However, slavery was already an outdated means of production given the advances in technology available. On top of that, when the Union Army marched through the South, the Union burned crops and destroyed farms.
The South had few railroad lines and factories which compounded its ability to keep up with changes in the economy. The Southern economy had to diversify by making iron and steel, and by building textile mills with a trained labor force and infrastructure to move product. Compounding the problems mentioned above was the occupation of the South by federal forces, extreme racial resentment on all sides (sharecropping became an option for former slaves creating a cycle of debt), and really, the South didn't recover economically from the Civil War until well into the 20th Century.