While all of these factors could negatively impact Grange membership in various ways, the most likely factor that caused a decline in Grange membership would be declining wheat prices.
The Grange (formally the National Grange of the Order of Patrons of Husbandry) was established to support farmers, and a significant drop in wheat prices would directly affect the financial stability of farmers, leading to reduced interest in or ability to participate in agricultural organizations like the Grange. When farmers face economic hardships due to low prices for their crops, they may prioritize immediate financial concerns over membership in such organizations.
Other factors, like rising railroad prices and variances in freight costs, could also contribute to dissatisfaction, but the direct economic impact of declining crop prices is typically a more immediate and pressing issue for farmers. Drought conditions could also affect membership, but they are often considered more of a natural disaster that may lead to temporary declines in production rather than an economic trend influencing long-term organizational membership.