The western has been one of the most prolific genres in American filmmaking, despite repeated shifts in popularity and content. Whether as nostalgic longing for a romanticized past or a critical reevaluation thereof, westerns continue to offer a characteristic blend of myth and history through which this quintessential American genre has influenced filmmakers worldwide.

Westerns are typically set in the transmississippi West during the second half of the nineteenth century, but might reach as far back as the colonial era or forward into the twentieth century, and geographically into Mexico, Canada, or Alaska. Most plotlines revolve around such staple characters of the "Wild West" as cowboys, Indians, settlers, outlaws, sheriffs, and the cavalry.

A great number of Hollywood stars (e.g. Gary Cooper, Errol Flynn, James Stewart) appeared in westerns during their career, but no actor was as closely identified with the genre as John Wayne, whose career spanned five decades and nearly ninety westerns. Wayne was the biggest male box office star in the United States between 1950 and 1965, working with such influential directors as John Ford and Howard Hawks on many classic westerns. Anthony Mann, Raoul Walsh, and Delmer Daves also directed several well-regarded westerns prior to the 1960s. Influential directors since the 1960s include Sam Peckinpah, Sergio Leone, and Clint Eastwood.

Inexpensive, formulaic "B" westerns, also known as series westerns, were produced in large numbers during the 1930s and 1940s. Even in the 1950s, however, when western films with a revisionist or political agenda began to emerge at the same time as television production heightened, action-packed but formulaic plotlines continued to dominate low-budget features.

Revisionist westerns set out to address the violence and racial prejudice at the core of the westward expansion of the United States, a trend that carried on into the 1960s and 1970s with director Sam Peckinpah’s ruminations about violence and changing times, or Italian director Sergio Leone’s cynical spaghetti westerns. After the spectacular failure of Michael Cimino’s high-budget Heaven’s Gate (1980), many declared the western dead, but the genre yet again proved its resilience in the 1990s – though that most recent run of westerns is beyond the scope of this collection.