How did the plantation lead to the Civil war?

Answer 1

The success of the cotton trade caused Southern leaders to neglect manufacturing industry and assert the need to continue the institution of slavery.

Congress was levying tariffs to protect US manufacturing industry, which was nearly all in the North. The South were the ones who needed cheap imports. So these tariffs looked like the North taxing the South, causing enmity between the two sections.

The North was also increasingly reluctant to allow the creation of new slave-states. This meant that the South was likely to be outvoted in Congress, which would tend to pass laws that favoured the North.