During the antebellum period, what was the main product produced by both the north and the south

Which of the following statements is true about germany's use of u-boats?

What was the main argument of plessy in plessy v. ferguson

7. how did the early egyptians use the flooding of the nile river to their advantage? they diverted the water to flood their enemy's lands and destroy their crops. they created an easier way to travel to the mediterranean sea and the indian ocean. they established a new water-based athletic event for the ancient olympics in greece. they devised an innovative irrigation system, which created a surplus of food.