Alison,
The interesting thing is Kathleen was written by a man named Westendorf, my spellage may be wrong, not your typical Irish name. And if my memory is correct, he wrote it in Canada for his wife who was dying of TB. Here in America we have a great tradition of real Irish songs heving been written by German Jewish guys in New York city. Which is a long way from Irish Catholic guys living in Derry. :-)
Don.
I would add:
When I'm Gone, by Phil Ochs
Red River Valley
Katie Cruel
Anything from the Sacred Harp
You are My Sunshine, by Jimmie Davis
As long as the Grass Shall Grow, By Peter Le Farge
Power and Glory, by Phil Ochs
Follow The Drinkin Gourd
Three Fishers
The Queensland Overlanders
The LogDrivers Waltz
Spanish Is The Lovin' Tongue