From the reading and video Jurgis truly believed in the American Dream: What was the American Dream? How did the Meat Packing Industry and Jurgis's experiences destroy that myth?
High school is not your subject.
The American Dream was that the United States was perfect (or close to it). Everyone is free and can get rich if they work hard and keep their noses clean. Jurgis found that he was nearly a slave in the meat packing family. He barely made enough to support a family. Conditions were hellish, both in the factory and in his home.
Upton Sinclair wrote this novel to highlight the terrible plight of people, especially immigrants who worked in jobs that produced goods for other people. The irony is that his message almost got lost when people and Congress learned of the unsanitary conditions that produced meat that everyone ate. The brief passage about the man who fell into the lard vat and was processed as "Armor's Pure Lard" caused Congress to pass a pure foods act.
http://en.wikipedia.org/wiki/The_Jungle