This is a timeline of the history of the first people to arrive in North America in around 25,000 BCE, how they lived, and how their civilisations developed over thousands of years. It is thought they crossed the land bridge connecting Asia and North America. Hunters, and later hunter-gatherers, then spread south and east after the Ice Age ended. They used plants, built land sculptures and earth pyramids, traded across the continent, and followed nomadic patterns.