Answer:
Opposed them
Step-by-step explanation:
The American System was an economic plan created by Henry Clay which consisted of implementing a high tariff to support internal improvements such as national roads in the West.
It aimed to allow the US to grow and prosper and become an industrialized country.
The South opposed the American System and the built of national roads in the West because they already had rivers to transport goods and did not agree to pay for roads and canals that would not bring them any benefit. The South demanded that the tariff would be applied to them as well.