If the King of England hadn't made them buy slaves, there wouldn't have been a problem.
The planter elite brought on the war because they were afraid that the election of a "Black Republican" threatened the long-term viability of slavery. Jefferson Davis was a member of that elite but just one man and far from the worst. Slavery was well entrenched in the South before he was born, and the Revolutionary era politicians in the South who thought that slavery was evil were afraid to try to do anything about it, because it would be political suicide to try.
The planter elite were sort of like the union bosses of their day. Get what's good for themselves and to hell with everyone else.
As I remember it the Virginia effort to stop slavery was three generations earlier — it was Queen Anne that prevented it.
Jefferson may have desired to cite that long past in incident but it was Patrick Henry that raised it in speeches.