I am currently reading 'Guns of The South' by Harry Turtledove.

It's an "alternate history" novel about a group of South African Boer mercenaries who travel back in time to the American Civil War to arm the Confederacy with AK-47 assault rifles. The South of course wins the war. Johnny Reb has just stormed the White House and forced "Honest Abe" to sign armistice papers.