The Boss of the Plains was a lightweight all-weather hat designed in 1865 by John B. Stetson for the demands of the American West. It was intended to be durable, waterproof and elegant. This design and the term "Stetson" eventually became all-but-interchangeable with what later became known as the cowboy hat.
The Boss was designed with a high crown to provide insulation on the top of the head, and a wide stiff brim to provide shelter from both sun and precipitation for the face, neck and shoulders. The original fur-felt hat was waterproof and shed rain. Overall, the hat was durable and lightweight. On the underside, the hat included a sweatband, a lining to protect the hat, and, as a memorial to earlier designs, a bow on its sweatband, which had the practical purpose of helping distinguish the front from the back. The original designs were natural in color with four-inch crowns and brims; a plain strap was used for the band.
For years, Stetson worried about the waterproofing, and finally decided to make his hat of beaver felt. It took about 42 beaver belly pelts to produce a high quality hat. Because of the tight weave of most Stetson hats, it was waterproof enough to be used as a bucket. One story tells of a cowboy crossing a long dry stretch of prairie. His canteen sprung a leak. He saved the drinking water by carrying it in his Stetson. Stetson featured advertising of a cowboy watering his horse with water carried in the crown. The wearer could also use the brim to direct water to a person's mouth. A high quality hat in good condition was also viewed in some places as a status symbol.
The straight-sided, round cornered, flat brimmed original Boss of the Plains design dominated for about twenty years. Most 19th-century photographs show that the hat doesn't have an intentional crease at all. Most hats were kept open crown. However, through use, abuse, and customization by individual wearers, hats were modified from their original appearance. In particular, the crown would become dented, at first inadvertently, then by deliberate choice of individual owners. The brim was often rolled or curved and ornamentation was sometimes added. Often, these creases and brim shapes began to reflect where a particular hat owner lived or worked, and in some cases, even cowboys on individual ranches could be identified by the crease in their hat.