Oh, I should mention that I know Virginia split apart well into the war.

Somewhat. Eastern Virginia had long retarded the economic growth of Western Virginia, and their adherence to the Jeffersonian vision of America didn't encourage economic development in the same way that the Pennsylvania legislature did. Because of the antiquated division of political power until the 1850's the Eastern part of Virginia completely dominated the state legislature giving them an essential veto over the west. By contrast no region in Pennsylvania was so dominant so "log rolling" was common ensuring that the economic interests of the entire state were represented. In Virginia there were no east-west rails until the 1850's and the James River and Kanawha Canal were very poorly built for the carrying of coal, only allowing one/third of the ideal load. The insistence on local government also gave county courts in Virginia extreme power that didn't create a state-wide environment friendly for business again unlike Pennsylvania. It is important to note however that in the 1850's most coal produced in Virginia was done west of Richmond not in Appalachia, that didn't come until years after the Civil War, in part because of the same insistence on local government. Pennsylvania also invested in state-wide surveys, awarded money to people who could find a use for their more common anthracite coal, and gave favorable concessions to businesses for lengthy periods of time. In short I would say Virginia's long standing retardation of the west contributed, and certainly Western Virginians looked at envy to Pennsylvania, but I wouldn't say the issue alone was a prominent source for the division.

I'd recommend Old Dominion, Industrial Commonwealth Coal, Politics, and Economy in Antebellum America which compares Virginia and Pennsylvania