http://www.publiusforum.com/2011/01/01/a-glossary-of-hat-terms-words-definitions-and-styles/
https://archive.is/v4ldP
Stetson:
Contrary to popular opinion, a “Stetson” is not a generic name for a cowboy hat anywhere but popular fiction which used the term as a general slang for “cowboy hat.”
With his famous “Boss of the Plains” model hat (seen below), John B. Stetson did help popularize the western-styled, wide-brimmed cowboy hat, of course, and he encouraged people to think of the name Stetson when talking hats, but he neither invented the cowboy hat nor was its only producer.
Few real people called their hat a Stetson unless it actually WAS a hat made by Stetson!
John B. Stetson is the founder of the famous company which began its long life in 1865.
John was from a hat making family, too. Along with his father and brothers he helped start the “No Name Hat Company” (amusingly, they could never arrive at a company name so agreed to call it “No Name”) before John stepped out on his own and started his eponymous hat company.
Later on, his brother, Stephen L. Stetson, tried to start his own hat company named the Stetson hat company, but older brother John sued him to stop the use of the famous brand name.
Later all Stephen L. Stetson hats carried a legal disclaimer that said the hat was “in no way affiliated” with John B. Stetson hats. The actual Stetson hat company ceased manufacturing hats, closed its doors and was defunct by 1974. But the name was sold to a series of companies and now exists really as a brand name as opposed to an actual hat company.