1. It limited and disrupted the seasonal rounds of the Native Americans: Native Americans would migrate with the changing seasons to follow herds, fish, or gather different resources. The new settlers not only disrupted these patterns, but also hindered access to resources and traditional hunting or fishing grounds.
2. It spread diseases that the Native Americans had no immunity against: diseases like smallpox, measles, and influenza spread due to contact with Europeans, decimating the Native populations and weakening those who survived.