In 1860 Maryland voted very marginally for Southern Democrat Breckenridge over the Constitutional Union's John Bell.
Neither Republicans nor Northern Democrats were a major factor, except that if their votes could be added to Constitutional Union Bell's, they make a majority for Unionists.
But Maryland's Governor Hicks, elected in 1858, was an American Party, aka "Know Nothings", today we'd say, "America Firster".
America Firsters were, basically, the old Southern Whigs before that party split over slavery.
Later, America Firsters were thoroughly discredited by the events of December, 1941, and have now been somewhat revived under President Trump.
America Firsters were the former Southern Whig allies of Northerners who became Republicans -- they were separated from Republicans by slavery.
But once slavery and all its associated racism are removed from the political equation, America Firsters Constitutional Unionists are the Southern branch of Northern Republicans -- and visa versa.
And the old Whigs were fully capable of carrying majorities in the South -- did so twice, in 1840 and 1848 -- so long as slavery was not on the ballot.
And that is the genius of President Trump -- to bring back Southerners to their "America First" traditions and unite with Northern "make America great" traditions.
Maryland's Governor Hicks was as solid for the Union as could be hoped for.
And when push came to shove, Maryland itself was roughly two-thirds Union, one-third Democrats.
FR posters like DiogenesLamp and others have regaled us endlessly with their economic theories of why the North refused to accept Cotton State secessions.
They say proposals for Southern "Free Trade" had Northerners quaking in their economic boots.
Anything, even the bloodiest war, was preferable to Southern "Free Trade" DiogenesLamp tells us.
So Southern "Free Trade" was the real reason for Civil War, they say.
But in this article, in December 1860, we see the question of Southern "Free Trade" discussed in very reasonable terms and exposed as the fraud & deception it truly was.
I recommend the article, a key point of which is that for six-sevenths of South Carolina's population, everything they lived on was already "free trade" and only luxury goods of the wealthiest one-seventh were taxed, and in amounts that could not be enough to support an independent South Carolina government.
For this article at least, the whole idea of Southern "Free Trade" was bogus.