The western is the only genre that matters. If you point out some other great American work in a different genre, I will say that it is also a western. All the great gothic and weird tales come from this. The western is America without frills (unless it’s on some cowboy’s jacket) and deals with the real-world concern of savages stealing your cattle and raping your womenfolk. You are never too far from a violent primordial past. You do not have to go far in time or space in this country to find a morose and depraved landscape that consumes its inhabitants.
American atavism. John Steinbeck set his retelling of the Book of Genesis, East of Eden, in Salinas Valley, California. This is something that you can only do in this country. His novels set in Mexico show that Latin America is a continuation of European medieval feudalism and Mesoamerican society. America is a society that has a temporal beginning. I think that is why heritage Americans have a fondness for genealogy, as finding their first American ancestor is akin to finding Adam, with the same mythos. Rewinding the clock by a century turns each main street in this country into nothing but a church, a courthouse, and a brothel. Adding anything else would be superfluous.
The same deserts that hosted outlaws and Indians would see the first nuclear tests less than a century later. Cormac McCarthy speaks of this. He also stated that he only respected authors who “deal with issues of life and death,” as those were the only issues that mattered. Some of the better works of this genre in the 21st century are his later novels and True Detective Season 1.