The American frontier includes the geography, history, folklore, and cultural expression of life in the forward wave of American expansion that began with English colonial settlements in the early 17th century and ended with the admission of the last remaining western territories as states in 1912. This era of massive migration and settlement was particularly encouraged by President Thomas Jefferson following the Louisiana Purchase, giving rise to the expansionist philosophy known as "Manifest Destiny".
A "frontier" is a zone of contact at the edge of a line of settlement. Leading theorist Frederick Jackson Turner went deeper, arguing that the frontier was the defining process of American civilization: "The frontier," he asserted, "promoted the formation of a composite nationality for the American people." He theorized it was a process of development: "This perennial rebirth, this fluidity of American life, this expansion westward...furnish[es] the forces dominating Americancharacter." Turner's ideas since 1893 have inspired generations of historians (and critics) to explore multiple individual American frontiers, but the popular folk frontier concentrates on the conquest and settlement of Native American lands west of the Mississippi River, in what is now the Midwest, Texas, the Great Plains, the Rocky Mountains, the Southwest, the West Coast, and Hawaii.
In 19th- and early 20th-century media, enormous popular attention was focused on the Western United States (especially the Southwest) in the second half of the 19th century and the early 20th century, from the 1850s to the 1910s, a period sometimes called the Old West or the Wild West. Such media typically exaggerated the romance, anarchy, and chaotic violence of the period for greater dramatic effect. This eventually inspired the Western genre of film, which spilled over into television shows, novels, comic books, and video games, as well as children's toys and costumes.
As defined by Hine and Faragher, "frontier history tells the story of the creation and defense of communities, the use of the land, the development of markets, and the formation of states." They explain, "It is a tale of conquest, but also one of survival, persistence, and the merging of peoples and cultures that gave birth and continuing life to America." Turner himself repeatedly emphasized how the availability of free land to start new farms attracted pioneering Americans: "The existence of an area of
free land, its continuous recession, and the advance of American settlement westward, explain American development." Through treaties with foreign nations and native tribes, political compromise, military conquest, establishment of law and order, the building of farms, ranches, and towns, the marking of trails and digging of mines, and the pulling in of great migrations of foreigners, the United States expanded from coast to coast, fulfilling the dreams of Manifest Destiny. Turner, in his "Frontier Thesis" (1893), theorized that the frontier was a process that transformed Europeans into a new people, the Americans, whose values focused on equality, democracy, and optimism, as well as individualism, self-reliance, and even violence.
As the American frontier passed into history, the myths of the West in fiction and film took a firm hold in the imagination of Americans and foreigners alike.