onehellofausername

The Southern Victory series by Harry Turtledove. Follows from the South winning the Civil War up through WWII with the US and Confederates being bitter rivals throughout.

This is why, as an English teacher, I like to just give a ballpark for length, and just say it should be as long as it needs to be to get the point across successfully. If you answer the prompt in full, it should be plenty long enough.