The document summarizes the migration of early peoples to North and South America from Asia over 15,000 years ago. It describes how during the last ice age, lower sea levels exposed a land bridge called Beringia that connected Asia and Alaska. Many scientists believe the first Americans crossed this land bridge on foot, while others believe they arrived by boat. They hunted large ice age animals and eventually spread throughout the Americas. Around 10,000 years ago, some early Americans in Mexico began farming maize and other crops, leading them to establish permanent settlements and develop unique cultures across the Americas.