My own great great grandfather settled in frontier Minnesota in the 1860s from Norway (assigned to move there by the immigration department of the time). It was still very sparsely populated in the 1860s, and was on the edge of the frontier with the Sioux Indians controlling much of the territory. The Federal government had reached an agreement with the Sioux to pay for land, but during the tense and financially constrained period of the Civil War, the government fell behind on annuity payments. So the Sioux retaliated by attacking and killing 600+ immigrants that had settled in the land the Sioux had sold. My ancestors barely escaped, their house was burnt down, and the ensuing wars with the Sioux persisted for several decades afterwards.

http://law2.umkc.edu/faculty/projects/ftrials/dakota/Dak_acc...