The singer sees a pretty girl and asks her to marry; she says she prefers to live single. He calls her beautiful, and wishes he had her somewhere else. She turns him down again; he is foolish to ask. He says his heart will break, and leaves
"O'Reilly from the County Leitrim" shares many lines with "John (George) Riley (II) [Laws N37]." The difference between the ballads is that in this one the man is not the Reilly she has been waiting for for five years so she won't go with him to Pennsylvania.
Maybe this is what Laws N37 points to for "John (George) Riley II": "According to Cox, this is a modified form of the "Young Riley" ballad found on broadsides by Catnach, Such, no. 83, and Fortey, no. 341 (Harvard VI, 186)."
The lyrics of the first four verses of Pete Seeger's "John Riley" on PeteSeeger02 [John (George) Riley (II) [Laws N37]] and Martin Reidy's "O'Reilly from the County Kerry" on IRClare01 are very close. As noted above, the ballad endings are completely different; in the middle, Seeger's Pennsylvania is "Phoenix Island" here.
Mary Delaney's "Phoenix Island" on IRTravellers01 ends with the rejected suitor wishing to witness the girl's funeral and the girl answering that that will not happen.
Also collected and sung by Kevin Mitchell, "O'Reilly from the County Cavan" (on Kevin and Ellen Mitchell, "Have a Drop Mair," Musical Tradition Records MTCD315-6 CD (2001)) - BS