Realism, frontier realism, and naturalism were the literary movements during the period of 1865–1915. How can I write a short response explaining how the historical events during this time period influenced literature between 1865– 1915.
Prior to the Civil War, Romanticism held its sway over literature and art; however, the post-war world had seen too much carnage to go back to the Romantic idealistic world portrayed in the antebellum literature and art. Author Andrew Ladd says that, “with such brutality in the world, it had become difficult to see the beauty in nature and the inherent goodness of the human spirit. The era of American romanticism had come to a violent end." (Romanticism and Transcendentalist: 1800-1860, 82). Simultaneously with the Civil War, westward expansion was also taking place during this time period, which was often bloody and fraught with trials and tribulations. The writers living during this time period had seen both the brutality of the Civil War, as well as the brutality and harsh reality of westward expansion. With the brutality in the country as a whole, Romanticism did not stand a chance, and gave rise to Realism. Frontier Realism, of course, rose with the westward expansion.
As far as Naturalism goes, its rise was partly due to Darwin's writings and ideas published in the late 1850s. In light of the horrors witnessed in the 19th century, perhaps a picture of humans as simply animals would make more sense to the reading public, as it would have nothing to do with morality. Naturalist literature is marked by the treatment of human actions as simply biologically or socio-economically determined.
The end of your stated time period also leads up to the First World War, which put the final nail in the coffin of Romanticism for the world at large. The war claimed 17 million military and civilian lives and left an estimated 20 million wounded. There was simply no going back to the Romantic world of antebellum writing and art.
The Civil War had a major impact on literature during this time period. The horrors of the war shook people up and created a more pessimistic outlook on life. This was one of the first wars that was photographed so people had images to look at even if they were not involved in the war itself. The saying "a picture is worth a thousand words" is definitely applicable in ths case.
Realism came into play in large part out of need as a result of the war. People had something to write about but did not at the time have the right "tool" to do it. Realism/realistic novel was that tool. Romanticism, which came before realism, did not lend itself to write about the new perspective of society post Civil War.