The dance schools such as The New York Society of Teachers and Arthur Murray, did not formally begin documenting or teaching the Lindy Hop, and other forms of Swing until the early 1940's. The ballroom dance community was more interested in teaching the foreign dances such as the Argentine Tango, Spanish Paso Doblé, Brazilian Samba, Puerto Rican Meringue, Cuban Mambo, Cha Cha, English Quickstep, Austrian Waltz, with an occasional American Foxtrot and Peabody.
In the early 1940s the Arthur Murray Studios looked at what was being done on the dance floors in each city and directed their teachers to teach what was being danced in their respective cities. As a result, the Arthur Murray Studios taught different styles of undocumented Swing in each city.
From the mid 1940s, the Lindy Hop was stripped down and distilled by the ballroom dance studio teachers in order to adapt what they were teaching to the less nimble-footed and the older general public who paid for dance lessons. They took the very basic moves of the Lindy Hop, chose the easiest of them, and based the footwork not on the Lindy Hop, but on the Foxtrot. Additionally, the ballroom teachers -- enamored with their formal Latin dances -- added the Latin hip movements to this new dance. As a result, the ballroom dance studios bred and developed a Ballroom Swing which vaguely resembles swing dancing.
If this was not enough, the ballrooms conspired to decieve their customers. The instructors would go out to a public event and perform the Lindy Hop. When the people asked what they were dancing, they would tell them it was the "Jitterbug" or that it was the "Lindy Hop." This part was true, they had done a performance of Lindy Hop, but when these people signed up for the Lindy Hop classes, they would be taught, instead, this new Ballroom Swing. This Ballroom Swing is now often called "Triple Time" East Coast Swing, and is most often the first form of swing that people are taught today because it is easy to learn.
In the 1950s, American Bandstand -- hosted by Dick Clark -- was considered the television show to go to if one wanted to learn the latest "in" dances. Because the music played on the show was too quick for the Ballroom Swing's triple-steps, and because of censorship issues with "wiggling hips," the street version of Ballroom Swing -- popularly also known as "Jitterbug" -- was what teens saw, and emulated. Because American Bandstand was a nationally broadcast show, this "Single Time" East Coast Swing (the street version of Ballroom Swing), became popular among teens nationally, and the stolen name "Jitterbug" was applied to it by most of the nation. Because two different dances now shared a common name, the Lindy Hop would later regain its original name so as to clarify the confusion.