Believe me...rural MD is just as much the "South" as Alabama. Same with rural parts of South Central Pennsylvania.
South Central Pennsylvania was never much influenced by the South. It's just that Appalachia was at one point strongly influenced by Pennsylvania, and other parts of Pennsylvania have changed a lot since.
Option 1. MD and DE are former slave states with sizable rural Black populations. There couldn't be a better definition of what a Southern state is, if rural KY, WV and MO hadn't been abandoned by Blacks well-nigh entirely in the mid-20th century.
You'd be surprised how many confederate flags I see in some of the rural areas around here. I heard someone say that they saw more confederate flags in Perry county (a few miles north of here) then they ever saw in the South. Also remember, many of the towns (even Gettysburg) had a lot of Southern sympathizers during the Civil War.