"Poor Paddy Works on the Railway" is a popular Irish folk and American folk song (Roud 208). Historically, it was often sung as a sea shanty. The song portrays an Irish worker working on a railroad.
There are numerous titles for the song, including "Pat Works on the Railway" and "Paddy on the Railway" and "Fillimiooriay". "Paddy Works on the Erie" is another version of the song.