During the early 1800s, what factor most contributed to the south having an agricultural economy?

The south had fertile soil and a warm climate

In the southern states the soil is more appropriate for agriculture; also is worth mentioning that in this time began the rise of industrialization in general as a way to increase production, affecting all the industries in the country who could use technological development to increase and simplify production. The southern states were well-known for the quality of their agricultural productions, thus resulting into further investment in this field.