How did these event raise tension between the north and the south?

Question

Mexican American War

Missouri Statehood

Election of 1860

Preston Brooks beats Charles Sumner

Invention of the Cotton Gin

Nullification

Answer 1

Mexican American War - Would salvery be allowed in the new territories acquired by the U.S.?

Missouri Statehood - An agreement between the North and the South and passed by Congress in 1820 that allowed Missouri to be admitted as the 24th state in 1821. The North's attempt to force emancipation upon Missouri when it applied for admission as a slave state in 1819 rankled white southerners, and they threatened secession during the debates over the conditions under which Missouri should be granted statehood. The debates resulted in a compromise that involved the drawing of a line through the Louisiana Purchase territory prohibiting slavery north of the latitude 36°30′ and allowing it in the south.

Election of 1860 - When Abraham Lincoln was elected, southern states felt that their way of the life, their "peculiar institution," was threatened.

Preston Brooks beats Charles Sumner - On May 22, 1856, Brooks beat Senator Charles Sumner with his Gutta-percha wood walking cane in the Senate chamber because of a speech Sumner had made three days previous criticizing President Franklin Pierce and Southerners who sympathized with the pro-slavery violence in Kansas ("Bleeding Kansas").

Invention of the Cotton Gin - Southern planters were in desperate need of a way to make the growing of cotton profitable. Long-staple cotton, which was easy to separate from its seeds, could be grown only along the coast. The one variety that grew inland had sticky green seeds that were time-consuming to pick out of the fluffy white cotton bolls. Whitney was encouraged to find a solution to this problem by his employer, Catherine Greene, whose support, both moral and financial were critical to this effort. At stake was the success of cotton planting throughout the South, especially important at a time when tobacco was declining in profit due to over-supply and soil exhaustion.

The most significant effect was the growth of slavery. While it was true that the cotton gin reduced the labor of removing seeds, it did not reduce the need for slaves to grow and pick the cotton. In fact, the opposite occurred. Cotton growing became so profitable for the planters that it greatly increased their demand for both land and slave labor. In 1790 there were six slave states; in 1860 there were 15.

Nullification - The nullification controversy of 1832 was a major milestone in the national debate over federal versus state authority. Coming at a time when agitation over slavery and other issues that tended to divide the country along sectional lines was growing, the nullification controversy brought the states rights debate into sharp focus.

Nullification is the legal theory that a U.S. State has the right to nullify, or invalidate, any federal law which that state has deemed unconstitutional.