In The Red Badge of Courage (1895), Stephen Crane delves into the concepts of bravery and heroism through the perspective of Henry Fleming, a young man filled with romanticized notions of war. Henry's illusions are shattered when he joins the Union Army and faces the harsh realities of battle during the American Civil War.

Ernest Hemingway's The Old Man and the Sea (1952) narrates the poignant yet victorious tale of an elderly fisherman's relentless struggle with a massive marlin in the Gulf Stream, off the Cuban coast. This grueling challenge tests the old man's endurance as he strives to conquer nature.

Jack London's “To Build a Fire” (1902) is another naturalistic story highlighting humanity's struggle against the forces of nature. In this narrative, a man's survival hinges on his ability to start a fire in the frigid wilderness.

Facing Facts: Realism in American Thought and Culture, 1850-1920 (1995) by David E. Shi offers an accessible overview of the Realistic movement in the arts during the late 19th and early 20th centuries. This book is an invaluable resource for students studying the history, literature, art, or architecture of that era.

Theodore Dreiser's Sister Carrie (1900) stands as a pinnacle of literary Naturalism. The novel vividly portrays life in New York and Chicago at the turn of the century through the intertwined stories of Carrie's unexpected rise from a destitute farm girl to a celebrated actress, and Hurstwood's tragic descent from a respected tavern manager to a vagrant.

William Graham Sumner's What the Social Classes Owe to Each Other (1883) articulates a classic application of Darwinian principles to human society. The work asserts the all-encompassing beneficial law of “survival of the fittest,” which dictates the state of all social conditions. The book's answer to the question posed in its title: nothing.