Mr. rockefeller is sometimes described by historians as a "robber baron". does that sound like a positive or negative characterization to you? why?

The description of Mr. Rockefeller as ''robber baron'' is definitely a negative characterization. The reason why it is a negative characterization is that it insinuates that Mr. Rockefeller was a man of great power, and used its power to gain more wealth and even more power by stealing from the people bellow him in the hierarchy.

Now, the stealing part can be seen from two perspectives. The first one by using force, and taking the money or the possessions of the people. The second one being by stealing through making murky business and illegal things behind closed doors.

d. it adversely affected american productivity

chemicals that are toxic to plants