Complex sentence: The song is a work song, and makes references to the construction of the American railroads in the mid- 19th century; the tarriers of the title is a mild slur in referencing the workers, drilling holes in rock to blast out railroad tunnels.
Split into simpler sentences: The song is a work song, and makes references to the construction of the American railroads in the mid- 19th century. The tarriers of the title is a mild slur in referencing the workers, drilling holes in rock to blast out railroad tunnels.