We empirically investigate the relationship between agricultural development and proximity to military forts in Kansas, Nebraska, and Colorado in 1880. Agricultural investments are substantially higher in counties where a military fort is present, suggesting that military forts stimulated agricultural development on the Great Plains. However, the reverse is not true; there is no statistical support for the notion that forts necessarily located in counties where substantial development was already occurring. Moreover, we found that while the presence of a military fort has the effect of increasing agricultural development, there is no evidence that such a presence sustained agricultural development.