I think it was due to tax laws and such rather than a prohibition one. You're supposed to pay a special state tax on alcohol in each state. Since Coors didn't brew in the east, it was illegal to bring the untaxed beer into a state for distribution. Mississippi still has a similar law that keeps out microbreweries from other states.
whomod said: I generally don't like it when people decide to play by the rules against people who don't play by the rules. It tends to put you immediately at a disadvantage and IMO is a sign of true weakness. This is true both in politics and on the internet."
