Why did southern farmers oppose Hamilton’s plans for the economy

They opposed Hamilton because he defended wealthy merchants from the East Coast. These merchants favored tariffs in order to protect themselves from foreign competition notably from Britain, they wanted free trade for their own economic interests.

Explanation:

They did not want to pay taxes to help the northern states.

answer; i do believe that the (14th)fourteenth amendment is the correct answer

nothing certain is known about what happened, but it seems that the country declined gradually, perhaps due to bad government, or, more likely, due to a series of bad harvests, which resulted in widespread and recurrent famine.