Supposedly he wasn't, but given the popularity of Fɾҽҽmαsσɳɾყ in that day, I wouldn't be surprised if he was.
His father was from that "revolutionary" more Newtonian era, the wigs, the tricorn hats, the Enlightenment knickers, but Lee wasn't a Freemason. Mosby, Davis, Jackson, Stephens weren't either. Sam Houston, however, was.
The cινιℓ ωαr was influenced by Fɾҽҽmαsσɳɾყ, and other things as well. Not that it matters, but I think the weight of Fɾҽҽmαsσɳɾყ came out on the side of the North anyway.