A period known as 'The Western Civil War of Incorporation' lasted from the 1850s to 1919. Others, including the Library of Congress and University of Oxford, often cite differing points reaching into the early 1900s typically within the first two decades. The archetypical Old West period is often cited by historians to have occurred between the end of the American Civil War in 1865 and the 1890 U.S. The legends, historical events and folklore of the American frontier have embedded themselves into United States culture so much so that the Old West, and the Western genre of media specifically, has become one of the defining periods of American national identity.
This era of massive migration and settlement was particularly encouraged by President Thomas Jefferson following the Louisiana Purchase, giving rise to the expansionist attitude known as ' Manifest Destiny' and the historians' ' Frontier Thesis'.
The American frontier, also known as the Old West, popularly known as the Wild West, encompasses the geography, history, folklore, and culture associated with the forward wave of American expansion in mainland North America that began with European colonial settlements in the early 17th century and ended with the admission of the last few contiguous western territories as states in 1912.
