Why did so few cities develop in the southern colonies

Because the southern colonies revolved around agriculture

Explanation: the southern colonies made most of their profit through growing crops like cotton, Tabaco, and sugarcane, making densely populated cities redundant, this is the same reason why there were more slaves in the south, because they had more of a use for them and slaves could work on the plantations, if there was a slave in the north they would most likely do similar jobs to a housemaid.

the right answer is the end of world war ii

after the end of a global wwii all the nations involved, in an attempt to create an organization to maintain world peace. this agreement would work settling international disputes via negotiation and arbitration instead of leading the issues escalate to another war.

increase in population