Mass culture exploded in the last decade of the nineteenth century, when American culture saw the emergence of multiple new forms of mass communication—such as newspapers, book-length nonfiction exposés, and theater networks. People now had common ideas and stories to discuss, which brought them together and helped to create popular culture.
Urban tabloid newspapers, such as Joseph Pulitzer's New York World and William Randolph Hearst's New York Journal, pioneered mass communication through news stories. These publications used hyperbolic banner headlines, interesting photographs, and witty cartoons, and expertly crafted the art of using "yellow journalism" to grab the attention of the public. The goal of yellow journalism was to create sensationalist titles that emphasized salacious stories, crime, and drama. Facts that counteracted the tawdriness of a story could be left out. These headlines would ensure that lots of people would purchase the paper, driving the growth of mass culture.
As part of the popularity of these newspapers, muckraking became a common way to expose business corruption, helping to usher in the Progressive Era and chip the veneer off of the Gilded Age. An example of yellow journalism in action was when the USS Maine blew up in Havana, Cuba, and the press ran dramatic headlines that accused Spain of attacking the ship maliciously. These headlines were meant to sell papers and drum up support for the Spanish American War. It worked. It was never confirmed that Spain blew up the USS Maine; historians now believe that the explosion was likely not due to foul play.
Another source of mass communication came in the form of book-length nonfiction exposés. The era of big business had created monopolies across America. Muckrakers in the late 1800s were determined to expose the corruption that created the fortunes of men like Carnegie, Vanderbilt, and Rockefeller. Many in American society read these books and became enraged at the injustices they learned about. For example, muckraker Henry George published the book Progress and Poverty in 1879, which focused on exposing the corruption of America's political economy. He claimed that poverty in America was caused by private land ownership and greed. He excused monopolists, such as Vanderbilt and Morgan (who created the railroad monopolies), of bankrupting American society. His capstone work would set the stage for other muckrakers of the twentieth century, like Upton Sinclair and Ida Tarbell.
Theater also brought Americans together in the latter half of the nineteenth century. Thomas Edison was the first inventor to successfully project moving pictures, in 1896. However, the first true motion picture did not grace movie screens until 1903. However, before movies, Americans had theater. After the Civil War, the application of electric lighting made theatre more enjoyable. Likewise, improvements to scenery meant that playwrights could be more creative, and better seating meant that people in the audience could watch plays more comfortably. In 1896, the Theatrical Syndicate was formed and created booking networks around the United States. (This organization would be challenged by the Shubert Organization some years later.) In this way, many people would have been able to see the same plays as the company made its way around the US, adding to mass culture.
Overall, the creation of mass culture in America was inevitable. As new technologies continued to bring people common sources of information and entertainment, society became more and more interconnected.