Was it like you called operator for these numbers? Or my second guess is I've seen letters on American button phones, so it could be a convention that ABC - 1; DEF - 0; etc.? I'm just piecing this together from random stuff.Year: 1966
Phone numbers starting with letters is how all phone numbers in most of the U.S. prior to 1969 used to be set up. The letters represented the area or neighborhood the exchange could be found in.








