Historians sometimes define the American West as lands west of the 98th meridian, or 98° west longitude. This line of longitude runs though the middle of Texas and Kansas up through the eastern third of Nebraska and the Dakotas. Some definitions of the region include all lands west of the Mississippi or Missouri rivers. For the complete story of western expansion in the United States, see Westward movement in America.
Regardless of the precise boundary line used, the western frontier differed in many ways from the eastern United States. Much of the West had a drier climate than that of the East, and western terrain often proved much harsher. As a result, immigrants to the West had to adapt and find new ways of doing things to survive. Their efforts were aided by improvements in transportation, communication, farm equipment, and other areas.
