How do I go about protecting future employees from the discrimination I faced?

Remarks were made by my direct supervisor about my skin color and the fact that I am a nursing mother. She told me on multiple occasions that I shouldn't nurse because pumping takes up too much time. She also knew I am Hispanic and asked with a discusted look on her face why are you so tan? I said because im Mexican, and she continued to dirty look me and talk about my race. She even went so far as to call me the following Sunday to tell me ahe doesn't believe im hispanic. I reported all of this and explained that I have logs as well as witnesses but my hr manager asked what do you want me to do and explained that my supervisor worked in a store with mostly Hispanic employees and they loved her. Making it seem as though they doubted the validity of my claim. I quit due to this inaction and syated in my notice that she was the reason. What can I do?