The American frontier comprises 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 mainland territories as states in 1912. "Frontier" refers to a contrasting region at the edge of a European-American line of settlement. American historians cover multiple frontiers but the folklore is focused primarily 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, and the West Coast. In 19th- and early 20th-century media, enormous popular attention was focused on the Western United States in the second half of the 19th century, 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 comic books, and children's toys, games and costumes. This era of massive migration and settlement...