A.support “free silver” to raise prices for farm goods
The Populist party surged in the 1890s from the discontent of farmers in the South and Midwest of America against the Democratic and Republican Parties that ignored their interest and difficulties. Farmers suffered from a bad economy, that made it very difficult to prosper: they suffered from poor marketing, falling prices and lack of credit facilities, some were sunken in debt, etc.
So one of their actions as a party was to firmly advocate for the unlimited coinage of silver. Farmers believed that this measure would increase the price of their crops, would help debtors to pay their debts more easily.