I decided to take a look at a genre that is important (as it highlights what has happened in history) but also difficult to read (lots of bad, terrible things have happened in history); but also wanted to look at the very small but mind blowing section of speculative fiction; alternate history...where authors say "what if" and change a thing or a few things and see where the story takes them.  I talk about books written for teens and adults as usual, and divide the list between the two.  Hope you enjoy!