Set = who live? the American West = the Western United States?

If a book, play, film, etc is "set" in a locale or time (or both) that means the story entirely or mainly happens in that place and/or time. A novel set in 15th century China (but not written in that time or place). A film set on Mars in the year 2500. A play set in a duchess's bedroom.

The "American Old West", the "Old West" or "the Great West" is often used to describe the area west of the Mississippi River during the 19th century. Sometimes called the "Wild West". Home of cowboys, gunfights, six-shooters, the OK Corral, sherrifs, Liberty Valance, etc.

American West refers to a period in US history with cowboys, Indians, cattle herding, gold rushes, etc. It is set in the western US, but the term refers to the historical period as well. "Attributed to" means that people generally believe that person wrote or said it. If they knew for certain, they would just say it was written by someone.

correction: sheriffs

Thank you.