The earliest recording of “El Corrido Pensilvanio” seems to be the one made by Pedro Rocha and Lupe Martinez in 1929, but the song was probably written several years earlier. During World War I (1914–18), the governments of the United States and Mexico formalized a policy referred to as “temporary admissions” in which American companies hired and transported Mexican laborers to the United States to address labor shortages. Many workers were brought to Pennsylvania. During World War I, workers were transported to work on the Pennsylvania Railroad, and in the early 1920s they were hired to work for the Bethlehem Steel Company. These experiences inspired the composition of “El Corrido Pensilvanio.”