Joe Hill, born Joel Emmanuel Hägglund and also known as Joseph Hillström, was a Swedish-American labor activist, songwriter, and member of the Industrial Workers of the World. A native Swedish speaker, he learned English during the early 1900s, while working various jobs from New York to San Francisco. Hill, an immigrant worker frequently facing unemployment and underemployment, became a popular songwriter and cartoonist for the union. His songs include "The Preacher and the Slave", "The Tramp", "There Is Power in a Union", "The Rebel Girl", and "Casey Jones—the Union Scab", which express the harsh and combative life of itinerant workers, and call for workers to organize their efforts to improve working conditions.

A hobo is a migrant worker in the United States. Hoboes, tramps, and bums are generally regarded as related, but distinct: a hobo travels and is willing to work; a tramp travels, but avoids work if possible; a bum neither travels nor works.