In the late 19th and early 20th century, growing corporate power and political corruption spurred the reform-minded Progressive movement. Progressive journalists engaged in what came to be called muckraking, a type of journalism that chronicles detailed accounts of political and economic corruption. Muckraking changed mass media in the United States. Today, most mainstream media outlets strive to remain nonpartisan and provide correct and factual information in news coverage. The work of modern investigative journalists reflects the muckraking tradition. These reporters provide in-depth stories on complex issues that often reveal questionable actions by public officials, business leaders, or prominent members of society.Until the 1920s, when radios became widely available, newspapers were the main form of reporting the news. With radio, news coverage changed from lengthy pieces to brief summaries of major events. Public figures could speak directly to the people. President Franklin Delano Roosevelt (1933–45) took advantage of the changing media environment to address the American people through the radio without his comments being filtered through the press. Each one of President Franklin D. Roosevelt's periodic national radio talks known as a fireside chat. In the 1950s and 1960s, televisions became common fixtures in people's homes. Presidents began giving televised press conferences, and television news organizations began televising congressional hearings and the political parties' national conventions. News organizations could use powerful visuals as well as sounds to tell a story, which had a profound impact on how Americans interpreted events such as the civil rights movement of the 1950s and 1960s and the Vietnam War of the 1960s and 1970s. How public officials looked on screen became a tool of public appeal—or a disadvantage. In the 1980s the number of television channels available skyrocketed with the advent of cable networks. This gave Americans access to 24-hour-a-day news coverage. The information revolution brought on by the Internet changed the news media further. Individuals gained even more access to news—or commentary on the news—from a vast array of sources. Political movements and campaigns were changed by social media. Social media refers to all the online communication options that enable users to share ideas and information with their social networks. Social media enables individuals to communicate with nearby neighbors or strangers across the world and helps groups build far-flung support networks. These media also pose some disadvantages. People can find themselves in a filter bubble, the viewpoint isolation a person can experience based on Internet browsing and device history and social media connections. Social media can also create an echo chamber, a situation in which certain ideas and beliefs are reinforced through repetition and without the inclusion of competing ideas. In this way, the information a social media user receives reinforces existing points of view.