The cotton gin, new farmlands in the west, and the demand for cotton in northern and european textile factories led to

a)
an increase in demand for slaves in the years leading up to the civil war.

b)
a decrease in demand for slaves in the years leading up to the civil war.

c)
the development of an industrialized southern economy.

d)
the missouri compromise and the kansas-nebraska act.

The answer is A. an increase in demand for slaves in the years leading up to the Civil War.

Why is it A)? It is A because the cotton gin, new farmlands in the west, and the demand for cotton in northern and European textile factories led to an increase in demand for slaves in the years leading up to the Civil War. As a result, the South became even more dependent on plantations and slavery, making plantation agriculture the largest sector of the Southern economy.