hi! just a heads up that this sub is inundated with April Fools content right now, so if your post gets lost in the shuffle and is left unanswered, do resubmit when normal service has been resumed in a couple of days.

This confusion appeared as both the Rebel Alliance and the Confederacy of Independent systems fought against the established government of their time (the Empire and the Galactic Republic, respectively). I think the association first appeared in 23ABY, in "The Skywalkers", the HoloNet drama, and spread from there.