The classification given to this would be mineral ore. Ore is a sediment taht contains a useful amount of a particular element. This is usually extracted from the Earth and refined in order to extract this valuable element. In order for ore to be mined, its concentration of the desired material must be high enough to make the effort worth it.
It was the "<span>(D) First Battle of Bull Run" of the Civil War that occurred first, since it was this battle that "set the stage" for the future of the conflict and made it clear that the war would not be quickly won. </span>
