Gun Fights in the American West
Needless to say, this popular misconception mostly comes from the film industry. Western movies and paperbacks were once among the most revered genres of all time (in Europe, strangely, as well as the United States), and have only recently begun to wane in popularity. Though notorious outlaws of the era are often described with gusto as ruthless murderers responsible for hundreds of kills, actual gunfights in the early American West were extremely rare, and were certainly not taken lightly by either citizens or law enforcement.
Outlaw gunfighter stories were popular, though, because they were exciting, scary, and glamorous, and the appropriation of them decades later by popular writers and the burgeoning film industry only added to their endurance.