Ok so, at least Six justices have to vote at all to decide an issue, and no matter how many justices are voting, a Majority Vote must be attained. So if Nine justices were to vote, Five justices would have to be for one side, as five would be majority over the four remaining justices.
In the 1860s, most factories were located in the North of the United States, mostly because the South was largely agricultural and remained this way for many years.