How did the civil war affect industries in the north?
1.the north closed many industries.
2.industries could not meet wartime demands.
3.industries became more mechanized.
4.northern industries had to ask the south for

I believe the answer is: 3.Industries became more mechanized.

Due to the civil war, the southern states were forced to freed the slaves that they held for their plantations. Because of this, the plantations on southern states were forced to find out other options to produce their products. This lead to the implementation of many mechanical tools for producing the goods, since it's far cheaper and faster than hiring human labours.