What effects did the European arrival in America have on the native Americans

The Europeans brought with them diseases which were unknown to natives. Many died as a result. The Europeans brought sugar which natives liked and as a result now had tooth decay for the first time. Europeans traded the natives goods in exchange for trinkets of little value but the natives didn't know that at the time.

Native peoples of America had no immunity to the diseases that European explorers and colonists brought with them. Diseases such as smallpox, influenza, measles, and even chicken pox proved deadly to American Indians.