What was the primary way that the economy in the south differed from the economy of the north

I believe the answer is: The farms of the South raised agricultural products.*

Since the industrial revolution in United States centred mostly on northern states, the norther states were predominantly produce manufactured products. The southern states who still rely in slave labour in their plantations predominantly raised agricultural products

The primary way that the economy in the south differed from the economy of the north was that the South's economy was almost entirely agricultural and relied heavily on slavery, whereas the economy of the North was almost entirely mercantilist and had very little slavery.