Conflicts between the Sioux Indians of the Plains and the US Army spanned from

Major conflicts between the Sioux and the U.S. Army took place from the 1860s through the 1890s. These included Red Cloud’s War in the 1860s and the Great Sioux War of the 1870s; the 1890 Wounded Knee massacre marked a final major clash. Therefore, the correct choice is “the 1860s to the 1890s.”

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