In the 19th century, whites were expanding into frontier lands within many New World areas and encountered many hostile, warlike tribes, particularly in the Pampas and Patagonia (in Argentina plus Chile), the Great Plains and Southwest (in the United States), New Zealand, and South Africa. The whites fought wars against these tribes and it oftentimes took decades to fully subdue them. Which tribes were the most formidable of all and took whites the most effort to subdue - the Mapuche, Tehuelche, and other Araucanized tribes in Argentina/Chile? The Sioux and Comanche of the Great Plains? The Apache of the American Southwest? The Maori of New Zealand? Or the Xhosa, Zulu, Sotho, Tswana, etc. of South Africa?