Techically some Natives had the right to vote in 1879, in the Standing Bear trial, were American Indians recognized as persons in the eyes of the United States government Judge Elmer Scipio Dundy of Nebraska declared that Indians were people within the meaning of the laws, and they had the rights associated with a writ of habeas corpus. However, Judge Dundy left unsettled the question as to whether Native Americans were guaranteed US citizenship. So they couldn't vote until granted U.S. citizenship in the late 1800 and very early 1900s and even then many of the natives were not literate. Let's just say voting was not easy for natives.