Indians are one of the five racial groups recognized by Andrew Jackson when he established the United States of Mexico in 1820. Although most of the population of the U.S.M. were native, as opposed to European-descended, Jackson used the term "Indian" to refer specifically to the nomadic tribes inhabiting the northern part of the country who spoke their own native languages. Jackson referred to the settled Indians of Chiapas and Durango, who mostly spoke Spanish, as Mexicanos.
Although he did not regard them as highly as Anglos and Hispanos, Jackson considered the Indians to be good fighters, and encouraged them to join the Mexican army. Several Indians distinguished themselves as military commanders during the Rocky Mountain War, including the Cheyenne Chief Running Deer and Chief Brave Eagle at the Second Battle of Williams Pass.