Use precolonial to describe anything that happened or existed before a powerful country moved into and took ownership of a region. Precolonial North America was inhabited by Native Americans.
Everything changes once a region is colonized, and the time before colonization can be described as precolonial. Autonomous tribes existed across North America for centuries before European colonizers arrived on the continent, and that precolonial history includes large-scale agriculture, trade with foreign countries, and construction of towns and cities. Precolonial is from pre-, "before," and colonial, from the Latin colonia, "settled land."