A nifty alternate-history novel. I've wondered sometimes what makes one civilization flourish and another just fall to the ground chewing at itself with its own disembodied teeth.
In brief, North America is colonized and populated by African Muslims who thrive in part because of their white European slaves. (It would be nice if there was any reality -- alternate or otherwise -- where the Irish didn't get their asses kicked regularly, but that's probably not Steven Barnes' job to write.)
Lion's Blood is way more complex than that single sentence and really a good read. It also shares a singular honor with Battlefield Earth (sorry, but it's true!) in that there's a separate audio "companion" album released. Of course, in this case, the music is really cool stuff by Heather Alexander -- Irish slavery songs. Get the book and get the music, too -- they're greeeeeeat!