Gerardo Licón’s KCET story on pachucos, young Mexican-Americans in the WWII era, is excellent and taught me a lot about a culture of which I had only foggy and cliché-ridden ideas. What makes it LH material is the following paragraph:
This brings us back to the question regarding why pachucos in Los Angeles seemed to speak more [African American] jive than pachuco caló [slang]. It is because Mexican Americans in Los Angeles were greatly influenced by other groups in the U.S. compared to the Mexicans that were more recent arrivals to Los Angeles, especially from the border area of El Paso, Texas and Ciudad Juarez, Chihuahua, Mexico. Border cities have a greater degree of language mixture (something akin to Spanglish) than cities further inland as well. At that time, El Paso was the primary point of entry for Mexicans into the U.S. The slang name of El Paso was “El Chuco.” Many Mexicans would cross into the U.S. and go to El Chuco, or in Spanish slang, “Pa’l Chuco.” When young Mexican Americans took trains along the Southern Pacific railroad, through Tucson, Arizona, to Los Angeles for wartime employment opportunities, they were referred to as pachucos. They brought their form of border Spanglish to Los Angeles with them. Mexican American zoot suiters native to Los Angeles spoke more jive; migrants from El Paso spoke pachuco caló with more of a Spanish-language and Spanish slang influence. This is also why when reporters asked Mexican citizens, after the Zoot Suit Riots, where pachucos had come from, many said they came from El Paso.
Naturally, I was dubious about this derivation, and sure enough, when I looked it up in AHD I found a different etymology:
[American Spanish, person from El Paso, pachuco, possibly alteration of payuco, yokel, from Spanish payo, peasant, perhaps from Gallego Payo, Pelagius (considered a typical peasant name).]
And googling brought me this webpage by the redoubtable Barry Popik, whose first paragraph reverses Licón’s causation:
El Paso is infrequently called “El Chuco” or “Chuco Town”/”Chucotown.” The term comes from the word “pachuco,” a Mexican Spanish Caló dialect word of disputed origin, dating from the 1930s-1940s.
After that it has as many citations and theories as you could possibly want.