For years, “the internet” has told us with certainty that Pius XII issued an indult to American Catholics dispensing them from the obligation of abstinence on the Friday following Thanksgiving. No one ever has a citation to an authoritative source, though.
Some years ago, your scribe downloaded the post-war Pian AAS volumes and used search tools to look for such an indult. That was an uncertain effort, but it yielded no results.
Now someone more industrious has conducted a new search and found a similar dearth of evidence of any permanent indult. You should read all about it at the NLM. The long and short is that there almost certainly never was a blanket, perpetual papal indult for Americans to eat meat on the Friday following Thanksgiving. There were, by contrast, numerous local dispensations, a fact that in and of itself militates against the existence of the blanket indult of the internet rumor.
In other words, the fabled “turkey indult” is almost certainly a myth.
Nashville TLM 