Who is Crazy Horse "Sr." from Crazy Horse and Custer: The Parallel Lives of Two American Warriors and what is their importance?

Crazy Horse is the father of the man more commonly known as Crazy Horse. He is a medicine man, meaning he doubles as the local cleric and physician. Crazy Horse is a member of the Oglala people, one of the main subgroups within the tribes known as the Sioux. He lived on the Great Plains during the late 1700s ad 1800s, and he was exposed to white men and other tribes moving into his peoples' range of activity because they were being forced Westward, but this was nothing that the Eastern tribes had not sometimes done earlier in history.