What term is most often used to describe changes in the South's economy following Reconstruction?
The phrase most often used was "New South," as the South managed to re-invent itself rather quickly and efficiently following the end of Reconstruction. Influential leaders of the post-reconstruction South realized that the days of "king cotton" had past, and the South must industrialize if it were to survive. These leaders called themselves "redeemers" as they believed they had the obligation--and right--to "save" the South from Northern domination. They promoted diversification of the southern economy, but at the same time worked tirelessly to retain white supremacy. Their political opponents called them "Bourbons," recalling the words of Napoleon Bonaparte that the former French royal family had learned nothing nor forgotten nothing from the French Revolution.
The first industry to industrialize in the South was textiles. The textile industry had previously been dominant in the northern states but moved south because of the abundance of cheap labor. A large number of textile mills were built in the south which created an entirely new economy and also increased the demand for cotton. Although cotton was no longer king, it did dominate much of the south's agricultural production as it was needed to fuel the burgeoning textile industry. Although slave labor was no longer available, tenant and sharecropper farming supplied the necessary labor to supply cotton to the mills.
Along with textiles, tobacco also saw something of a renaissance. The production of burley and brightleaf tobacco strains made tobacco production quite profitable. Brightleaf tobacco was first processed in Durham, N.C. with a bull appearing on the package label. This gave rise to the name "Bull Durham." At the same time, the Duke family of North Carolina founded the American Tobacco Company and made millions.
You should probably check your textbook to make sure of this answer because different texts will emphasize different words. However, the most likely answer to this is the term "New South." Alternatively, some books might refer to "industrialization." Both are talking about the same general idea.
Before and during Reconstruction, the South was overwhelmingly agricultural. The slave system, among other things, made it hard for factories to spring up in the region. This led to a situation where the South, at the end of Reconstruction, was relatively backwards economically. At that point, many books say, a "New South" arose. This was a South in which there were more factories producing things like textiles and tobacco products. There were more railroads. In general, the economy was moving more towards industrialization.