Earliest known work dealing with alternate history?

Inspired by BrainGlutton’s thread. There seem to be two kinds of divergent history stories: type A) one where time travellers directly or indirectly interfere with events in the distant past, creating alternate timelines (example, Bradbury’s A SOUND OF THUNDER and type B) where a divergent timeline is conceived of owing to apparently random changes in events and extropolated for its own sake, (say, Harris’ FATHERLAND.)

I assume those have antecedents. What are they?

IIRC, there was a book in the early 1800s which discussed what life would be like if Napoleon had won at Waterloo. It was a series of essays by historians, and the early alternate history book tended to be of that nature.

Murray Leinster’s “Sideways in Time” was an early piece of alternate history in the SF genre; it was published in 1934 and is often cited as one of the first fictional alternative history stories (i.e., not historians writing essays).

From http://en.wikipedia.org/wiki/Alternative_history_(fiction):

From Uchronia - the Alternate History site