.. and the late 1870’s to early 1880’s time frame for their depictions. It is likely because those were the days when Wyatt Earp and brothers were at the peak of fame, or because it was the time of cattlemen range wars.
Caroline Lockhart, famous Western novelist from Cody, Wyoming, wrote her stories about real people in her real time (1910’s) in reaction to all the favorite writers of the day like Zane Grey telling the same tales of 1880 with the good guy in the white hat and the bad guy in the black.
(Photos: Natural form in Western “high fashion” in “Deadwood” with proper corsetry (left), and a farmer’s daughter interpretation of the same in we don’t know which movie (right)