American society changed when the country became industrialized in the late 1800's and early 1900's. A few people owned businesses and became extremely rich, professionals and managers earned enough to live comfortably and became the middle class, but many unskilled workers and immigrants lived in extreme poverty. The poor people, and often their children, worked long hours under unsafe condition to afford enough to live in crowded apartments while the rich business owners did unethical or illegal things to get even richer. And since the politicians were often corrupt, they did little to change or regulate the situation.
But a new movement in journalism aimed to improve American society by exposing the wrongs. The muckrakers, who were given this name by president Theodore Roosevelt for their tendencies to only see the "filth" in society, used novels, books, magazine articles, cartoons, and photographs such as the ones in this video to shame politicians and businessmen into serving the public good instead of themselves. Their successes made life better for all Americans.
Although the times have changed, many of the issues remain. Modern-day investigative journalists expose these issues by using very similar techniques and, as this article shows, their work still brings about changes. Like the muckrakers, their goal is to make life in America better by exposing its problems.