In 1860, the South's economy was completely dependent on industry.

This statement is not true. South's economy depended on Agriculture.

Explanation:

A large part of the economy of south was dictated by agriculture.

Most of this agriculture was also happening in cash crops like cotton which was then either tilled in the industries up north or more often than not sold abroad in England.

The use of subsistence crops was also there in usually local small plantations.

The bigger plantations grew crops for sale and not for their own subsistence basically.

The region had not been industrialized.