Proof of jeans
From "A Brief History of Jeans:"
Jeans remained the workwear of the rough and tumble West well into the mid-20th century. They started to trickle out to the general public in the 1930s, as Hollywood Westerns started sweeping across movie screens, introducing audiences to macho types sporting jeans as they lassoed cattle, slung guns, and engaged in other cowboyish activities.
