There were twice as many Westerns on top 10 lists from 1900-1924 than from 1924-2014. Keep in mind that is 24 years versus 90 years. Cowboys really are a dying breed.
Western Books vs. Movies
A look at Western bestsellers and top movie premieres. This timeline portrays the decline of western novels and subsequent popularity of Western movies.
A look at Literature & Fiction and Historical Fiction through the century
As you can see, readership of Literature and Fiction and Historical Fiction has greatly declined from 1980-2014. From 1900-1980, there was a 76% chance readers would be reading a book from these two genres. From 1980-2014 this dropped to just a 15% chance.
The age of Literature and Fiction and Historical Fiction is seemingly over.
The fall of Literature & Fiction and rise of Mystery, Crime, and Thriller
A look at the trajectory of two different genres that seem to be pitted against each other. Literature and Fiction declines as Mystery, Crime and Thriller booms in popularity.