Some important quotes from "Life in the Iron Mills" involve poverty and the impact of industrial progress. This quote is an important introduction into the story:

A reality of soul-starvation, of living death, that meets you every day under the besotted faces on the street,—I can paint nothing of this, only give you the outside outlines of a night, a crisis in the life of one man.

The above quote highlights the main theme of the story: the life of hopeless degradation endured by members of the impoverished working class in nineteenth-century America. In her story, Rebecca Harding Davis documents an overwhelming soul-thirst that grips one man, Hugh Wolfe, who is a puddler in an iron-works factory. He yearns to break free from the vile coarseness of the life he must live. The narrator begs us not to judge Hugh for succumbing to temptation and taking Mitchell's money. Harding Davis’s narrator points us to the "slow, heavy years of constant, hot work" that Hugh has endured and asks us to judge accordingly.

The idiosyncrasy of this town is smoke.

The narrator tells us that his town is filled with smoke and that smoke engulfs every object, place, and building as far as he can see. Most poignantly, smoke "begrimes" every iron worker’s "skin and muscle and flesh." When not toiling in the factories, many men drink themselves to oblivion in order to forget the misery of their daily lives. Davis suggests that the smoke symbolizes both physical and spiritual enervation. The "idiosyncrasy" or distinctive feature of the town is indeed smoke: there is no escape from it. Thus, there is no reprieve from the burdensome lives its inhabitants must live.

I want you to hide your disgust, take no heed to your clean clothes, and come right down with me,—here, into the thickest of the fog and mud and foul effluvia. I want you to hear this story.

In this quote, Harding Davis highlights the toll inflicted on an unsuspecting population during the Industrial Revolution. In the nineteenth century, many immigrants flocked to newly-constructed factories. The Wolfe family, for instance, were Welsh immigrants. The pay from factory work, however, was poor and barely supported the subsistence lifestyles of these immigrants. With few marketable skills, the immigrants had little choice but to tread the path set before them. Many, like Hugh, suffered from debilitating illnesses, such as tuberculosis (from breathing in poisonous fumes on a daily basis).

Sin, as he defined it, was a real foe to them; their trials, temptations, were his. His words passed far over the furnace-tender’s grasp, toned to suit another class of culture...

The second quote from this passage highlights Harding Davis's Christian background. Although the preacher was likely not indifferent to the plight of immigrants, his sermon failed to resonate with someone like Hugh, a member of the immigrant working class. Davis suggests that, had the preacher exposed the reality of Christ as a brutalized figure, "wounded" for the "iniquities" and "transgressions" of mankind, then someone like Hugh might have “known the man” or recognized himself in Christ. Instead, the preacher's words failed to resonate with Hugh because they were so far removed from the reality of his dreary existence.