What U.S. military conflict was fought between 1870 and 1890 against Native American tribes?

The correct answer is the Indian Wars, which symbolizes a series of conflicts that occurred between the United States and various Native American tribes during the period from approximately 1870 to 1890. This timeframe is characterized by U.S. expansion westward and the consequent displacement and resistance from Native American tribes who were defending their lands and way of life.

The Indian Wars encompassed various battles, skirmishes, and the establishment of military campaigns aimed at subduing Native populations. Key events during this period included notable conflicts such as the Battle of Little Bighorn and the Nez Perce War. These conflicts were pivotal in shaping U.S. policy towards Native Americans and had significant implications for both the tribes involved and the broader American society.

In contrast, the other military conflicts listed, such as World War I and the Civil War, occurred at different times and revolved around entirely different issues and adversaries, such as global alliances and internal divisions within the United States, respectively. The Mexican-American War, which preceded the Indian Wars, focused on territorial expansion in the southwest rather than engaging directly with Native American tribes. Thus, the Indian Wars stand out as the appropriate answer for the conflicts specifically involving Native American tribes during this period.