Answer:
The nuclear arms race was an arms race competition for supremacy in nuclear warfare between the United States, the Soviet Union, and their respective allies during the Cold War.
A: The Civil War
Assuming that you're talking about the American (U.S) civil war, that is.
The civil war was a conflict between the rights of the (slave owning) states and the national government. A war about state rights.
The war of 1812 was between 2 independent, sovereign nations.
The great depression was just an economic thing.
The northwest ordnance, I have the least knowledge of, but it still wasn't between states and the national government.
Hope this helps.