What is the main idea/thesis of The Jungle?

The main theme
as laid down in Sinclairs is capitalism. He strives to vividly showcase
the negative implications of capitalism by painting the mirage that is the American dream in
contrast to the reality of wage slavery. Power and factors of production are held by a handful
of people at the top who exploit workers for maximum economic gains. Jurgis and his family
relocate to Chicago with a lot of hope and enthusiasm to work hard, acquire material wealth and
earn a better life. This is however not to be as his familys financial situation deteriorates
following an endless series of tragedies including the death of his wife and children. The
deplorable conditions continue to demoralize Jurgis until his encounter with socialism, a
philosophy that stands for comradeship among the workforce. It is at this point that he learns
about what capitalism is and its ripple effect on the structure of the society. Socialism is the
remedy to counter capitalism.