Oh yeah- I didn't recognize the title, but I did come across that stanza when I was doing the thesis. I think it dates from the 19 teens. It drove me nuts- trying to find a recording of a Mrs. O'Leary song- she's not mentioned in any of the Chicago Fire songs contemporary to the disaster. There's a Brian Wilson instrumental called "Mrs. O'Leary" (not the same melody as "Hot Time in the Old Town," and I seem to recall there was a Johnny Horton song that I was never able to track down.