A) when the United States gained new territories as a result of the Mexican War in the late 1840s, the nation had to decide whether to admit these lands as slave territories or free territories.
B)The cotton gin increased cotton production, so all southern farmers abandoned all other cash crops. They relied on cotton for wealth, and the south became known as the Cotton Kingdom.
C)The US Civil War caused the Federal Government to increase production of certain products to help fight the Civil War. The result was more profits for these industries.