Friedrich Engels became concerned with the plight of the working class in the aftermath of rapid industrialization in Europe. A member of the middle class, he quickly became compelled by guilt to make amends with his fellow man. Through a series of interviews, tours, and some heavy research he developed a theory concerning the social system of his day and why it was inferior and unjust.
In The Condition of the Working Class in England, Engels presents his findings for his intellectual peers to consider. He explains how disease, overcrowding, pollution, overwork, and factory accidents have decimated the working class population. He describes the living conditions of these people in their full, gory detail, hoping to instill a sense of righteous guilt in his peers. After decrying the rise of industrialization and urbanizations, he turns his attention to the upper class, or the bourgeoisie. Engels traces the rise of power of the upper class in Europe until he claims they possess a monopoly upon the necessities of life. They have positioned themselves as master over the working class, enslaving the majority of the population to fund the extravagance of the few, motivated only by pure greed. In the end Engels calls for the abolition of the bourgeoisie, in favor of a new method of social class which would distribute wealth more evenly.
Some years after publishing this book, Engels met Karl Marx in Paris. The two fast understood the profitability of their partnership, Marx building upon Engels economic ideas to form his communist manifest. They worked well together because of their common despair for the plight of the working class. It seems to be the case that Engels introduces himself at just the right time to help Marx complete his ideas.