What major geographical feature is theorized to have been crossed by migrants from Asia into America?

The correct answer identifies the Bering Land Bridge as the major geographical feature theorized to have been crossed by migrants from Asia into America. During the last Ice Age, approximately 20,000 to 30,000 years ago, sea levels dropped due to the massive amounts of water trapped in glaciers. This phenomenon exposed a land bridge that connected present-day Siberia in Asia to Alaska in North America. It is believed that human populations migrated across this bridge in search of food, ultimately spreading into various parts of the Americas.

This concept is supported by archaeological, genetic, and linguistic evidence that points to a common ancestry of native populations across these regions. The Bering Land Bridge provides a crucial explanation for the initial human settlement of the Americas and is a significant aspect of migration and adaptation studied in early American history.