How did the arrival of the Europeans in the Americas transform native cultures and life?

European newcomers dramatically changed native cultures and life. Here are five key changes:
War. The European newcomers were, in large part, there to conquer. The conquistadors of Spain even had it right in their title! Europeans, and later Americans, had a long and bloody history of conflicts with native tribes, ranging from Cortes's battles against Montezuma's Aztecs to Jackson's Trail of Tears in the mid 1800s.
Disease. Europeans brought with them devastating plagues. Smallpox and other deadly diseases, to which Native Americans had little immunity, ravaged entire populations.
Tools of conflict. Trade with Europeans gave natives access to steel weaponry, horses, and firearms. This transformed wars between native tribes.
Religion. Many Europeans traveled to the New World to escape from religious persecution and/or to evangelize their faith to nonbelievers. The slow spread of Christianity and the gradual conversion (willing or otherwise) of Native populations had a tremendous impact on the traditional cultures and religions of various tribes.
Agriculture. Farming was known to many tribes in the New World but was not universal, and domesticated animals were extremely rare. European farming techniques and tools, and the knowledge of cultivating sheep, goats, cows, and pigs, led to a substantial alteration of many natives' food dependencies.
http://www.native-languages.org/food.htm

https://www.history.com/topics/native-american-history/trail-of-tears