From André Bazin, “The Western: Or the American Film Par Excellence” (1953)

The western is the only genre whose origins are almost identical with those of the cinema itself and which is as alive as ever after almost half a century of uninterrupted success. Even if one disputes the quality of its inspiration and of its style since the thirties, one is amazed at the steady commercial success which is the measure of its health…..The western does not age.

Its world-wide appeal is even more astonishing than its historical survival…The western must possess some greater secret than simply the secret of its youthfulness. It must be a secret that somehow identifies it with the essence of cinema.

From Richard Maltby, Hollywood Cinema (2^nd ed.), p. 94

Loss of knowledge [i.e., of the genre's conventions by the audience] is particularly important in this case as Hollywood's production of Westerns declined precipitously after 1970, with barely a handful being made in the 1980s. Hollywood's apparent abandonment of what has been its most common genre raised questions about the critical arguments that claimed that the Western was central to the expression of an American mythology. Had the mythology changed, so that the Western was no longer relevant? Or had the mythology migrated elsewhere, to other genres, and if so had it changed its meaning in the process? Or had Hollywood somehow stopped articulating American mythology? Whatever set of circumstances brought about the change, it shows that even so self-generating and apparently transhistorical a genre as the Western is subject to historical forces.

from Richard Slotkin, Gunfighter Nation, pp. 642-43 (conclusion)

The "post-Western" genre map suggests that, while the Western may no longer provide the most important of our ideologically symbolic languages, the underlying mythic structures it expressed remain more or less intact. Action in the imagined world of myth-symbolic play still takes the form of captivities and rescues, still invokes the three-part opposition in which the American hero stands between the extremes of bureaucratic order and savage license, and still requires a racial symbolism to express the most significant ideological differences. What has been lost is not the underlying myth but a particular set of historical references that tied a scenario of heroic action to a particular version of American national history. The passing of the Western may mark a significant revision of the surface signs and referents of our mythology, but it does not necessarily mark a change in the underlying systems of ideology, which is still structured by its twin mythologies of bonanza economics and regeneration through savage war.