If we were to research the term "Gilded”, it refers to a thin layer of gold hiding poor metal. Being that, prosperity is the demand of gold and, the abuses in poverty the metal. By this era, by social Darwinism where the affluent believed that they were by nature superior, and the poor were naturally just less able. A time of trusts monopolies, abuse of workers and where the uncontrolled businesses lead to the Progressive Era.
Progressivism was created to oppose companies such as standard oil to create monopolies and spread their control across America.