The Populist Party's main base of support was represented by: Southern & Western farmers
O Northern industrial workers
O Bankers and investors
O Immigrants from Southern & Eastern Europe

(A) Southern & Western farmers

Explanation:

Cotton prices continued to fall and dropped to 7.5¢ a pound by 1892, or about the cost of production. Efforts by farmers to bring economic and political change within the Bourbon-controlled Democratic Party seemed hopeless. This led Mississippi farmers to turn to and support the newly created Populist Party.

The Populist Party consisted primarily of farmers unhappy with the Democratic and Republican Parties. The Populists believed that the federal government needed to play a more active role in the American economy by regulating various businesses, especially the railroads.

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the national congress's powers over the states were specific and definite: it had the sole power to negotiate treaties, declare war, and make peace. all powers not granted to congress were reserved for state governments. congress had no power to levy taxes, for example.