[BroJoeK]

Colorado tanker: "Franklin Pierce was very much a Copperhead Democrat, very willing to preserve the institution of slavery if that's what it would take to keep the Union together.
It's interesting that he wasn't pro-slavery enough for those New Yorkers."

"Copperhead" was a Civil War term for Northerners who supported the Confederacy.
"Dough-faced" was a pre-Civil War term for Northerners who supported the Southern slave power.

In 1836, Pierce "was attacked by the New Hampshire anti-slavery Herald of Freedom as a 'doughface', which had the dual meaning of 'craven-spirited man' and 'northerner with southern sympathies' "

During the Civil War, Democrat Pierce was highly critical of Republican President Lincoln, and was (mostly) spuriously attacked as a "copperhead".
Whether Pierce was an actual "copperhead" during the war is, seems to me, a matter of debate.

Bottom line: Northern Democrat Dough-faced President Pierce believed then, like all Democrats, that slavery was a pre-condition for Union, and without it, there could be no United States.
He opposed Lincoln's plans to reunite the nation by force.

[colorado tanker]

Thanks. Interesting.