This is a weird one. I am sure it happens in certain pockets, but I can't say that I have ever heard or directly experienced any form of casteism in my 16 years in North America. Having said that, my background is Tamil brahmin but I am not religious, don't go to temples, and don't wear a poonal (identifying sacred thread). As naive as it may sound, I hope my 6 year old son never hears the word caste in his life.