Dear English expert, help me translate this passage into Chinese! thank you

The "earliest Americans" were Indians. When people discovered America, about 500,000 Indians lived in this land. But after the arrival of the colonists, many were killed and the rest were driven to the western regions. After the independence of the United States, people from other countries poured in. Before 1890, most immigrants came from western Europe and northern Europe (regions); After 1890, most immigrants came from eastern and southern Europe (regions or countries).