Darwinism lead to widespread trend towards realism.
Explanation:
After Civil War new trend came in US during 1800 The people started to focus on realism. Romanticism as well as optimism ended. The questions that was asked previously the answer was given in a religious way but after the Civil War people now mainly focused on realism , they tried to get answer in a scientific way.
Literature played huge role , people tried to connect things with literature so that it becomes realistic. Now they stopped believing the fact that God always has a plan whatever he does its always good but now people mainly tried to find the cause in a more scientific way.
