Why would culture groups develop differently from each other?

This excerpt supports the idea that the sky chief valued

Situation #2: imagine that you are a newspaper editor in columbus, oh in 1863. the civil war has been dragging on for more than two years already and shows no signs of ending soon. you are aware that many black males are willing to enlist in the union army but you fear that they may be mistreated and abused by the majority of soldiers on either side in this war. write a one-page letter (double spaced) editorial for tomorrow's edition of the newspaper. the topic is military service in the union army by free african american males. in your editorial, take a clear position for or against having black men join the fight. be sure to give reasons for whatever position you choose to take.

Which factor contributed to the rise of african empires such as ghana and mali?