How did the growth of the railroads affect supply and demand for natural resources in the us?

The colonies depended on Britain for many finished goods, partly because laws prohibited making many types of finished goods in the colonies. These laws achieved the intended purpose of creating a trade surplus for Britain. The colonial balance trade in goods was heavily in favor of Britain; however, American shippers were able to offset roughly half of the goods trade deficit with revenues earned by shipping between ports within the British Empire. The largest non-agricultural segment was shipbuilding, which was from 5 to 20% of total employment. About 45% of American made ships were sold to foreigners.

the answer is migration

(d) rivers.

explanation:

civilizations developed around rivers because their waters provided places to hunt and fish. also, as the rivers flooded, the lands around them became fertile. this allowed them to support farming. this is especially true of the nile river, which flooded the same time each year.