Robert Higgs, "Railroad Rates and the Populist Uprising," Agricultural History 44 (July 1970): 29198

Mark Aldrich, "A Note on Railroad Rates and the Populist Uprising," Agricultural History 54 (July 1980), 42432.

Aldrich says rates relative to crop prices fell in the 1870s but rose through the 1880s and mid-1890s.