The first Americans arrived in North America around 30,000 years ago via a land bridge that connected Siberia to Alaska during an ice age. As the climate warmed, sea levels rose and the land bridge disappeared. These early peoples hunted large game like mammoths and used simple tools. Over thousands of years, their descendants adapted to different environments across North America, developing distinct cultural traditions and ways of life. Native American cultures shared some beliefs around spirituality and respect for the environment.