Abstract: Folk music plays an important role in any society. It provides the people with a voice of their own and a way to pass down their culture and history. As such, folk music has been the subject of many ethnomusicological studies. Unfortunately, most of these studies have focused on non-Western cultures and cultural trends. By looking at American folk music, and by applying ethnomusicological techniques to this study, we can gain a fuller and better understanding of American society as a whole. This is the purpose of this study, along with a specific focus on musicians and movements which have adopted the title of 'folk music' for their works. By looking at why these people attempted to associate their music with the 'folk,' we can gain a greater understanding of their motives and ideologies. This study will begin with a basic history of American folk music in general and a discussion of ethnomusicology to set the framework for the rest of the study. Chapter 2 looks at music of the unions in the early part of the twentieth century. Chapter 3 explores how 'folk' music was used as a political tool during the Great War (World War I); both for and against the war. Chapter 4 focuses on the clash between 'folk' music and the federal government, in the form of the House Un-American Activities Committee. Chapter 5 looks at the music of the 1960s and 1970s, with a focus on the Civil Rights Movement and the Vietnam War protests. The final chapter briefly shows how folk music is still being used, albeit to a much lesser extent, as a form of political protest.