After the civil war, what happened to the united states’s gross national product?

It proved that nation was strong. That even though this nation just got out of a horrific civil war, that now this nation is strong; basically the US prove to the world that i…ts no longer a little country, it proved to the world that its their turn to be world powers. For the first time in world history a citizen didn't name themselves after a state or a city or a kingdom, but now an American. The American states were no longer divided. But they have became the United States of America. 

Acase involving the laws of a single state.