Final answer:
The first migrants to North America likely arrived during the last Ice Age via the Bering Land Bridge or through coastal migration along the Pacific, significantly predating European and Polynesian contacts.
Step-by-step explanation:
The question explores the theories of how the first humans migrated to North America. The most accepted theories are that of the Bering Land Bridge and the coastal migration. According to scientific consensus, the first migrants probably arrived during the last ice age via the Bering Land Bridge that connected Asia and North America. This bridge was exposed due to lower sea levels as massive glaciers formed, and migrations occurred from about 10,000-14,000 years before present (BP). Additionally, the coastal migration theory suggests some people followed the coast of land across Asia and the Bering Land Bridge, then down the Pacific coastline to South America. Evidence from archaeological sites supports the possibility of such a migration. These theories indicate a pre-Columbian migration from Asia, preceding European exploration and Polynesian voyages.