"Go back to China"

I am Japanese American and I just moved to Manhattan, NY from Vermont and rarely experienced racism. I was on the subway coming home from work, and I noticed a man around 60-70 years old staring at me as I went on the subway. He walked up to me while I was sitting down. He asked me if I was supposed to be here. I asked him what he meant and he said, "Ch-nks aren't supposed to be here" and told me to "go the hell back to China." I was stunned and didn't know what to do. The people around me didn't do anything. I called my husband and told him what happened, and shortly after, I left.