B. American Indians had not been exposed to diseases from different parts of the world
Answer:
I'm going out on a limb here and assuming you're talking about the Civil War in the US, so the main disagreement was the idea of slavery.
Explanation:
<span>A long coastline, the slave trade, and good mineral deposits</span>
It helps us better understand the choices of the people before us. If we don't learn about its history then the lives lost fighting would be worthless.