The Populists of the late 1800s responded to the challenges of the Gilded Age by trying to get the government to do things that would help the common people, especially farmers. In particular, they tried to get "easy money" and government regulation of various industries.
The Populists wanted the government to be more flexible about money. They wanted it to allow silver money (as well as gold) and they wanted the government to make more silver money rather than less. This would have helped farmers who were in debt pay their loans more easily.
The Populists also wanted the government to regulate railroad freight rates. They wanted this so that the railroads could not charge them such high prices for hauling their crops. Some populists actually advocated government ownership of the railroads.
Overall, then, the Populists were trying to get the government to enact policies that would help farmers who were in debt and who were under pressure because of the power of the big companies like the railroads.