[P-40]

Slavery wasn't the sole reason, but it was the primary reason.


Slavery was one of a great many things leading to secession. It was also the one most exploitable to keep outside parties from joining in the war in an overt fashion.

[Heyworth]

It was also the one most exploitable to keep outside parties from joining in the war in an overt fashion.

Then the states that issued Declarations of Causes for secession probably shouldn't have mentioned slavery over and over again (with maybe a sidelong glance at tariffs, like Georgia, or Mexican bandits, like Texas) as the reason for leaving the Union. It's not like the north had a hard time convincing "outside parties" that the south was fighting to preserve slavery.