What I didn't know was that there was a series of riots in 1943 called the "Zoot-Suit Riot's". The riots started in Los Angeles and were primarily between white servicemen and Los Angeles's Mexican-American community. You might ask why would servicemen be involved in the riots. Well in 1942, the War Production Board instituted rationing on fabric. The regulations effectively banned the production of zoot-suits.
However, that didn't change the demand for them and bootleg operations sprung up to produce the sought after suits. That is what caused the bad feelings with servicemen. Wearing the suits was a visible rebelling against rationing and regulations. To the servicemen it was a slap in the face that people would so brazenly not help support their efforts.
Two incidents, one on May 30th 1943 and a second on June 3rd 1943, are thought to be the primary catalyst that started the ball rolling.
There you have it. A historical nugget for you to wow your fiends with.
Of course you can read all about the riots here.