We've already talked about the American Dream in "Society and Class," but that's not the only American ideal that Sinclair criticizes in The Jungle. There is also the melting pot: Jurgis and his family are recent immigrants from Lithuania. Their different cultural backgrounds and assumptions make many of their interactions with the American system even more difficult. Then there is the notion that America is the land of the free. While Sinclair does not seem to think this is the case now, he does allow for the possibility that we can keep striving for this ideal. One means to achieve freedom in the United States is through union organizing. For Sinclair, unions provide an important counterbalance to the business tycoons making the American worker so unhappy. The group solidarity these unions provide show the good side of contemporary America: it's not all price gauging and horrible exploitation after all.
By focusing The Jungle on an immigrant family, Upton Sinclair is able to explore American idealism from a more critical outsider's perspective.
In The Jungle, even though farmers and factory workers labor under completely different conditions, they are united by the seasonal, unstable nature of work in the American capitalist system.