The document discusses the history and development of the American West and Midwest from the late 18th century to the late 19th century. It establishes how the US expanded across the continent following independence and the establishment of states from the Mississippi River to the West Coast. The American Civil War and abolition of slavery in the 1860s were pivotal events. Western films later mythologized and interpreted this period of American history and pioneering spirit. The genre uses themes of binary oppositions between civilization and wilderness, inside and outside society.