The Confederacy and WWII

[True Federalist (진정한 연방 주의자)]

The south would have become allies with the british and the north with germany.

I see someone reads Turtledove.

Actually, if the South won the Civil War, that the North could turn anti-British is quite plausible despite the fact that Turtledove uses it.  That said, I'd expect such sentiments to show up sooner a la The Guns of the South than later as it does in Timeline-191.

That said, I wouldn't expect an Yanko-German alliance as the Germans weren't that interested in fighting the British.  Nor would an Anglo-Confederate alliance be an inevitable response to Anglo-Yankee fighting.

[True Federalist (진정한 연방 주의자)]

If the US and the UK got into fighting each otheras part of a World War, I could see the CS possibly joining the war on the US side if the British try a third party blockade as they imposed upon Scandanavia and the Netherlands in WW I. Territorially, the CS would have good reason to be interested in Jamaica, the Bahamas, etc., if only to get some additional English speakers if they've absorbed Cuba and/or more of Mexico in the interim.

[True Federalist (진정한 연방 주의자)]

The Confederacy wouldn't have lasted all the way up to World War II, if there would even have been a World War II.

While it is quite possible that the Confederacy would have fractured further, had the South gained its independence in the Civil War, it would not have been rejoining the Union later.