How did ancestors of native Americans arrive and why?

The ancestors of Native Americans are believed to have arrived in North America via a land bridge known as Beringia, which connected Siberia to Alaska during the last Ice Age, approximately 15,000 to 20,000 years ago. They migrated in search of food, following herds of large animals like mammoths and bison. Over thousands of years, these groups spread across the continent, adapting to various environments and developing diverse cultures. This migration is supported by archaeological evidence and genetic studies.