Farmers, laborers, ranchers, factory workers and such usually wore a outfit of sturdy wool, corduroy or denim trousers, a wool flannel, linen or cotton pull over shirt, a hat and sturdy shoes. Suspenders were commonly worn, though they were unpopular with men who had to bend or squat a lot, like sailors, cowboys or miners. Trousers did not have belt loops until the 20th Century.
The fellow on the left is a farmer around 1890-though he could just as easily have been from 1860. His collar button is buttoned. Unbuttoned collars are rarely seen. Click on the image for a larger view
The daily wear of working men also frequently made use of second hand or worn out pieces of sack, frock or morning suits. Vests were also frequently worn.
The man on the left in the picture on the right is wearing a cotton duck or denim bib apron, a common garment with blacksmiths or others doing particularly dirty work.
The substantial fellow next to him is typical of a western farmer or rancher, in his colorful shirt (red, blue or checked were the most common), smashed hat and (it would appear), neckerchief. His trousers may have been black dress pants in a former life.