The accompanying book to the Topic Records 70 year anniversary boxed set Three Score and Ten has a dust jacket picture featuring Killen with Frankie Armstrong; and one of the songs featured on both albums of The Iron Muse, The Blackleg Miners is track six of the sixth CD in the set.
Killen emigrated to the United States in 1967 and worked with Pete Seeger before joining The Clancy Brothers.
In 1971, the Clancy Brothers brought in the singer who had introduced the English concertina to the music mix, Lou Killen.
They recorded two studio albums on the Audio Fidelity label: Save the Land and Show Me the Way.
In the 1990s, Killen worked as the volunteer coordinator at the San Francisco Maritime Museum, also singing chanties there and interpreting to the public.