The Oneida were a member of the Iroquois League, a confederacy of six Native American nations in the Northeastern United States. The other members of the Iroquois League were the Mohawk, Seneca, Cayuga, Onondaga, and Tuscarora. The Iroquois League was formed in the 16th century and was known for its strong political and diplomatic structure. The Oneida were one of the most powerful members of the Iroquois League and played an important role in the history of the United States.