AKA Native American Day is Monday, October 8. I salute them all.
Here is what I have read (dates are subject to different opinions):
First migration: 20,000 years ago. Pre-Amerindian. A group related to the Ainu and the peoples of Australia and New Guinea. Now, some groups in Brazil and Argentina.
Second migration: 13,000 years ago. Amerindian. New World people called Native Americans, except for the other migrations listed here. Biggest migration.
Third migration: 4,000 years ago. Dine/Athapascan. Indians of Alaska, northwest Canada, and the Apache/Navajo.
Fourth migration: 1000 years ago. Eskimo (some people dislike this term). This includes the Inuit and the Yupik.
Please note: The native Hawaiians are Indigenous People (settled about 300 AD) who are of Polynesian ancestry—some researchers believe Polynesians settled parts of the west coast of both Americas.