I know next to nothing about covers and only have a couple, but this one struck me as interesting because of the Train Late marking on the reverse. This one came to me from one of my great-aunts, whose father was known as the family pack-rat (before I took over that particular prize!).
I wish I could see a clear date on the Philadelphia postmark, but if the 12/1/93 was the date that Mr. Bonsall received the letter, it seems to have taken a few days to get to him after that Late stamp was applied on 11/25. Were those Late marks applied when the PO received the mail or when the train finally arrived? In 1893, the 25th was a Saturday and Thanksgiving was the following Thursday, but that still seems like a long delay.

