It provided a means of transportation for goods across the country.
I want to say entrepreneurship, but there's also free economy enterprise, so... I'm gonna go with entrepreneurship.
Yes it would have because if Virginia had rejected secession, the prospect of Lee in command of Union forces rather than Confederate forces would have presented major problems for the Confederacy. The South would have lost a major economic and political asset, the state of West Virginia would never have been created, the war would almost certainly have been shorter. Interestingly, such circumstances might cast some doubts on how determined the North would have been to end slavery permanently.
Hope this helped!!