The manufacturing industry is a really important sector in the United States as it helped build the middle class after the second World War. In the early 21st century accounted for 10% of corporate profits. Unfortunately the employment in this sector is estimated to decline in the coming years.
One is right and one is wrong
The cotton gin was a machine for separating cotton from its seeds.
In summary, it would mean that slavery would be abolished, and that the nation would be in fact united, with (supposedly, it actually took a very long time for this to happen considering the KKK attacks) less racism in the U.S.