In 1890, Frank T. Hopkins and his mustang, Hidalgo, are part of Buffalo Bill's Wild West show, where they are advertised as "the world's greatest endurance horse and rider." Hopkins had been a famous long-distance rider, a cowboy, and a dispatch rider for the United States government; in the latter capacity he carried a message to the U.S. 7th Cavalry Regiment authorizing the Wounded Knee Massacre of Lakota Sioux. Hopkins was filled with regret and shame following the massacre and he falls into an alcoholic depression.