What About Fact Checking?

I just received a copyedited version of my forthcoming book, Africa Is My Home, and one of the things the copyeditor did is a whole lot of fact checking. I had no idea that was part of her job, but boy am I glad it was. Having seen serious errors in other books I've been fretting a great deal about the possibility of some in my own.  Thus my fascination with Dan Kois's "Facts are Stupid" in which an "essayist and his fact-checker go to battle over the line between true and false."  I...