During the period between 1890 and 1920, the United States was transformed from a largely agricultural and rural nation to one that was industrial and urban, and it wrestled with social problems concerning race, gender, and immigration. Progressivism emerged out of this context. By the turn of the century, a newly radicalized and resolute middle class launched an epic program of reforms, aiming to solve America’s social, economic, and political problems. Chicago became an important center of progressive activity. By the close of the nineteenth century, the city was home to businessmen who had achieved unprecedented levels of wealth. Meanwhile, Chicago’s numerous poor endured squalid conditions. The discrepancy between the promises made by the city and the lives lived by many of its inhabitants was depicted by progressive authors, including Upton Sinclair in his novel The Jungle (1906) and Jane Addams in her memoir Twenty Years at Hull House (1910). This chapter examines Chicago’s longer history of civic unrest going back to the Haymarket affair of 1886 and beyond, and it shows how Sinclair and Addams in different ways challenged Americans to come together with renewed moral purpose