Does anyone here know when the Tallahatchie flood, that is also featured in Mattie Delaneys song, occurred ?
I consulted John M. Barry's book, Rising Tide - The Great Mississippi Flood of 1927 and How it Changed America, which I highly recommend, it's an amazing book on many levels. But it does not have that specific information, so far as I could find.
But ... when the levee at Mounds Landing breeched on April 21st 1927, the resulting flood extended at least 50 miles to the east, some accounts say 69 miles. That is far enough to reach the Tallahatchie river. So one could reasonably assume it was on, or shortly after, the 21st April.