“Every state in the U.S.A. has something it can boast of”, as the song starts. Because of that, it means that states should find good opportunities to trade.
Trade occurs because of the theory of comparative advantage – when one person/area has a lower (opportunity) cost to produce. While this fun song lists fictitious items each state is good at producing, different states within the USA do have different products they produce efficiently and trade:
North Dakota: Oil
Oregon: Electronic Processors
And of course, Rhode Island is famous for more than what the song says, as it exports precious metal scraps!