This document summarizes westward expansion in the United States from the late 1700s to the mid-1800s. It describes how pioneers moved past the Appalachian Mountains through passages like the Cumberland Gap and settled new territories and states. Major developments that encouraged further western migration included the Louisiana Purchase, the Lewis and Clark Expedition, and completion of the Erie Canal. The document outlines the use of river transportation and wagon trains along routes like the Oregon Trail to settle lands beyond the Mississippi River, including territories in the Rocky Mountains and Pacific Northwest.