No one is trying to "erase history" by taking down statues of traitors such as Robert E. Lee.  Unless the history lesson is that these statues were put up in the first place.  I think the history lesson should be this: taking down the statue sends a message that our community is not going to support the reinvention of history -- the making of Robert E. Lee into a hero, and an "in your face" reminder to African-Americans of the days when their ancestors were slaves.