I'm currently a history major and I'm wondering if being a history undergrad would hurt my chances if I were to apply to a tax LLM program in the future. I know I'm thinking way ahead but I'm just considering all my options at this point. So do I need to worry about this or should I stay on my path and do well in tax classes during law school?

Completely irrelevant. You’re putting the cart before the horse on this one.