For what reasons were farmers angry at railroad companies?
After the Civil War the need for a transcontinental railroad was obvious. A number of railroads competed to complete a railroad stretching from the Mississippi river to San Francisco.
To assist and expedite this effort, the US Government engaged in land seizures, eminent domain, where it was deemed a railroad right-of-way was needed. This, of course, frequently split a cattle farmer's open range not to mention that his property was take often for less than what it was worth and even when he did not desire to sell it.