These actions simply accelerated developments of the previous twenty years, and the next two or three decades were a watershed in Salt Lake's history. The balance shifted during those years. By the 1920s, as Dale Morgan says, the city no longer offered the alternative to Babylon it once had, and the modern city had essentially emerged. The process has continued to the present, with Salt Lake City increasingly reflecting national patterns.

Since Utah became urbanized at about the same rate as the United States as a whole, Salt Lake faced the problems of urbanization and industrialization at the same time they were surfacing elsewhere, and it responded in similar ways. During the Progressive Era, for example, it established a regulated vice district on the west side, undertook a city beautification program, adopted the commission form of government in 1911, and that same year elected a socialist, Henry Lawrence, as city commissioner. The city languished through the 1920s, as the depressed conditions of mining and agriculture affected its prosperity. The Great Depression of the 1930s hit harder in Utah than it did in the nation as a whole. Salt Lake correspondingly suffered, making clear its close relationship with the world around it and its vulnerability to the fluctuations of the national economy; and New Deal programs were correspondingly important in both city and state.