Let me explain a simple concept for you - just because something is "history", doesn't mean it deserves a statue in the public square.  For example, King George is most definetly part of our nations history, but we don't honor him with statues do we?  The 9/11 hijackers were also a big part of our history.  Would you be equally concerned with someone toppling a statue of Mohammed Atta?  and if someone did topple such a clearly offensive statue would they be erasing that history?