The "CB" in CB radios stands for "Citizens' Band". These radios have a relatively short range and are most popularly used by contractors working in various parts of the construction industry as well as semi-truck drivers.
In the United States, CB radios gained popularity in the 70's with some help from the decreased speed limit of 55, which led truckers to warn other trucks of highway speed-traps. Other encouragement came from the media. Movies like SMokey and the bandit, shows like Dukes of Hazzard, and others encouraged the growth of CB radios. They also encouraged CB radio users to ignore the use of licensed call signs and use self appointed handles, which all too often contained the word "whiskey".
Today many CB radios have been replaced by cell phones and the Family Radio Service (walkie talkies). However, core users, mainly truck drivers, continue use of cb radios and will likely continue this use into the future.