Final answer:
The indigenous people of North and South America originated from Asia through a land bridge called Beringia. They migrated across this land bridge in search of food and later settlers came by boat.
Step-by-step explanation:
The indigenous people of North and South America are believed to have originated from Asia. Around 9,000 to 15,000 years ago, there was a land bridge called Beringia that connected Asia and North America. The first inhabitants of the Americas migrated across this land bridge in search of food. When the glaciers melted, Beringia was engulfed by water, and the Bering Strait was formed. Later settlers came by boat across the strait.
The indigenous populations of the Americas developed unique cultures as they moved southward, ultimately populating both North and South America. Some of these cultures include the highly complex Aztec civilization in present-day Mexico City and the woodland tribes of eastern North America. Recent research suggests that migrant populations may have also traveled down the west coast of South America by both land and water routes.
When Columbus arrived in the Americas, the indigenous population likely numbered around seventy-five million. These indigenous groups were diverse, with more than six hundred different tribes or groups in North America alone. They had varying lifestyles and economies, with some being mostly hunter-gatherers, while others engaged in extensive farming. The indigenous groups had their own political organizations, ranging from small bands with a designated leader to political confederacies and large urban populations ruled by monarchs.