Crazy Horse (Lakota: Tȟašúŋke Witkó in Standard Lakota Orthography, IPA:/tχa'ʃʊ̃kɛ wit'kɔ/, literally "His-Horse-Is-Crazy"; c. 1840 – September 5, 1877) was a Native American war leader of the Oglala Lakota in the 19th century. He took up arms against the United States federal government to fight against encroachment by white American settlers on Indian territory and to preserve the traditional way of life of the Lakota people.