There were several factors that led to the rise of the New South. The main factor that influenced this was the Radical Republican Reconstruction plan that was implemented after the Civil War. The South was completely destroyed after the Civil War. It was necessary to rebuild the South. The military was sent in to oversee the process of rebuilding the South.
As the South was rebuilt, there was an emphasis on diversifying the economy. The South was primarily agricultural prior to the Civil War. To change this one-dimensional economy, industries were developed in the South. This provided more jobs for southerners and made them less dependent on farming.
There was also a desire to provide former slaves with more freedom. Some former slaves were able to vote and run for political office. Attempts were made to provide more equality for the former slaves. Southern ways of life had been so much in favor of whites prior to the Civil War. During Reconstruction, laws were passed and amendments to the Constitution were ratified to try to make a more level playing field for the former slaves.
As a result, the South developed more industries. For a period of time, former slaves had more freedom and opportunities.