It's the Harry Turtledove series dealing with an alternate history of America that starts with the CSA winning the Civil War and what takes place over the next 80 years. It's a fascinating series of books (10 or 11, I lost count) and if you're familiar with American, world and military history you'll find lots of familiar events that don't take place in the exact same place or manner as what we know happened but that's part of the fun. You find yourself thinking "OK, that's based on such and such event!" or "Ah, that campaign follows this real one two wars earlier!" (Or in some cases events taking place today).
http://en.wikipedia.org/wiki/Timeline-191
I'd been working through the last book in the series for the past three weeks as free time allowed and just as it got to my bedtime last night I found myself 50 pages shy of the end. I knew good and well it was time to go to bed but I simply could not stop reading. It cost me an hour and a half or so of sleep but it sure was worth it!Timeline-191 is a fan name given to a series of Harry Turtledove alternate history novels, including How Few Remain as well as the Great War, American Empire, and Settling Accounts series. The name is derived from Robert E. Lee's Special Order 191, which detailed the Army of Northern Virginia's invasion of the Union in September 1862 during the American Civil War. The divergence occurs when Union forces do not find a copy of Special Order 191. The novels detail the consequences of this up until 1945 in the alternate world.
If you have a hankering for "what if?" stuff and haven't checked this series out, do it. Be forewarned though, I wouldn't let kids get into it since the language is pretty un-PC (remember, the South won and "that" word abounds) and they probably won't be familiar with the real events the series is based on unless you've been home schooling them and hit History pretty good.
Now I have more time to hang out here!