AHC: United Dakota and United Carolina

With a PoD after 1776 but before 1900, make North and South Carolina/North Dakota and South Dakota become a single state. Bonus if you can unite both of the aforementioned states in one single TL/scenario. Go!
 
The most straightforward scenario IMO would be a more intense Civil War coupled with a more radical reconstruction in which state lines were redrawn. Said reconstruction process proves costly leading to the resurgence of the Democratic party in which the Dakotas are admitted as a single state to avoid giving the GOP 2 additional senators
 
Top