Errol Morris returns to his NY Times blog with a five-part story about a photograph found in the hands of an unknown Union army soldier who died at Gettysburg. Start with part one. A description of the photograph made it into the newspaper and the identity of the man was pretty quickly discovered. But the story hardly ends there. My favorite part so far is the fourth, particularly the conversation between Morris and one of the unknown soldier’s descendants, archaeologist David Kelley.