In u. s. history, this is a term used to describe any unsettled land or territory west of the existing colonies. people that traveled to settle these areas were called pioneers.

Frontier--the land beyond the settled and established areas of the US was referred to as the frontier regardless of movement west.

The idea of the frontier and people willing to take the risk to settle it contributed to basic values of risk-taking, hard work, individualism, and progress essential to the creation of the US.