The one leg up, one leg down started in Chicago...it has to do with gang alliance of PEOPLE Nation or FOLK Nation...left leg up they roll under the FOLK Nation and vice versa.
The Big Overblown white t-shirt is common now and that originated in the west coast with Blood/Crip matters...
I cant think of the rappers name but the song goes...'In my white tee...in my white tee, I bang in my white tee I sling in my white all up in da club I spit game in my white tee i gleam in my white tee look clean in my white tee...hispanic, cracker, nigga look good in a white tee..."
crip/blood gangs were seen to sport giant white t-shirts as did this rapper and it blew up among the ghetto and bangers across america.
It's even in white suburbia.