Final answer:
Farmers' political protests in the late nineteenth century in the United States were primarily in response to the economic hardships caused by mild deflation, high tariffs, and challenging market conditions, which made it difficult for them to repay their debts and sustain their livelihoods, prompting them to form political alliances and the Populist Party.
Step-by-step explanation:
Main Reason for Political Protests by Farmers
The main political protests by farmers in the late nineteenth century in the United States were driven by the combination of mild deflation and other economic pressures. This mild deflation meant that the value of money increased, but the prices of goods, including agricultural products, fell. Farmers had borrowed heavily to buy land and expand production in a time when prices were higher. As prices of their crops fell due to overproduction and global competition, they found it increasingly difficult to repay their debts, which were worth more over time due to deflation. Moreover, unlike other sectors, farmers received little to no federal government assistance that would help maintain the prices for their crops.
Additionally, factors such as high tariffs on needed goods, manipulative commodity trading, exorbitant railroad freight rates, and a constrained supply of money severely impacted farmers. Their economic hardships were aggravated by a political system that appeared indifferent to their plight. In response, farmers began to unite into alliances and eventually formed the Populist Party in an attempt to cause political change and find solutions to their dire economic condition.