Through agriculture using the Euphrates river
Before Postmodernism the authors that made up the literary canon in the United States were mostly white men.
This literary movement called Modernism (or modernist literature) had a non-traditional style of verse and poetry. The writers from that time felt traditional poetry was outdated, and that new forms of expression and representation had to be done to express new sensibilities and beliefs.
In the cartoon, now-prosperous immigrants object to further immigration to America. The meaning behind the prosperous immigrants' shadows is that there is an underlying secret to how the immigrants became prosperous or their lives are in danger because they are more prosperous than the locals.
I don't get your question
I think that it focused on the welfare of humanity in society