Answer:
The invention of the cotton gin.
Explanation:
The South being favourable to the climate depended on agriculture. Before the invention of Cotton Gin, cotton production remains limited to slaves. With the coming of Cotton Gin by Eli Whitney in 1793, it reduced the time and labour by removing seeds from the fibres. It increased the need for slaves in the plantations for cultivating cotton and picking the cotton fibres in fields. Cotton cultivation became beneficial for the cultivators. Many of the states in America began to emerge as slave states as the cotton production turn out to be profitable.
The right of Northerns to own slaves
Oil was found in Alaska in 1977.
