What does milpa contain

A milpa is a field, usually but not always recently cleared, in which farmers plant a dozen crops at once including maize, avocados, multiple varieties of squash and bean, melon, tomatoes, chilis, sweet potato, jícama, amaranth, and mucuna Milpa crops are nutritionally and environmentally complementary.

Explanation:

b.   jim crow laws were enacted in northern states.

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.