In the 1850s, the North and South strongly disagreed about the production of cotton. the growth of commerce. the diversification of industries. the spread of slavery.

Although the North and the South disagreed on all these things at some point, it was primary the disagreement over the spread of slavery that defined this era in the US.

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MrDonovan MrDonovan · Answer 2 · 2019-01-16T21:40:07-05:00

The correct answer is the spread of slavery.

After the Mexican American War (1848) the United States gained several territories in the modern day American Southwest. This includes Arizona, New Mexico, Colorado, California, etc. One of the biggest issues was whether or not slavery would exist in these new territories. Determining whether or not slavery would exist in these territories was a controversial issue, as the decision could alter the balance of free and slaves states in Congress.

The North and South will continue to disagree over this topic went it comes to adding Kansas and Nebraska during the 1850's as well.