Explanation:
The Harlem Hellfighters were an African-American infantry unit in WWI who spent more time in combat than any other American unit. Despite their courage, sacrifice and dedication to their country, they returned home to face racism and segregation from their fellow countrymen.
The most recognized cause for the American Civil War is the conflict over slavery: the North found slavery unacceptable and wanted to abolish it, while the South needed slavery to be continued as their economy depended on it: they had plantations which required a lit of work and the plantations were more profitable if they didn't have to pay for this work.
Answer:
The neolithic revolution
Explanation:
This was a new start to all groups. It evolved hunter and gatherers into a more "civilized" population. The people found out about agriculture. People started to farm more which lead to a good source of sustainable food. This lead people to settle down and build in the area they farmed in. More food created a more stable life which helped increase the population.