https://www.wbur.org/artery/2020/06/03/16-statues-memorials-damagedRobert Gould Shaw, was an abolitionist. Matthew Broderick portrayed him in the film, "Glory."
I would love to be able to say that the damage was caused by alt-right types who insinuated themselves into the protestors, to make the Protestors and BLM look bad. But, I have no evidence of that.
In any crowd there are just stupid violent people who think - no they are
certain - that any statue indicates a horrible establishment person and their memory must be erased.
In the 1980's, the Young Democrats at the University of Washington got taken over by very far-left types (a proto-Antifa, if you will), who wanted to stop the placement of a monument on campus to an alumna who was a WWII hero. They were quoted as saying that they didn't want any monument to any Caucasian military fascist on campus. But, in reality, the alumna in question was a Native American who fought the Nazis. Sorry I can't find a cite on Google or Bing right now; perhaps someone out there with some affiliation with UW could find it.