What snake was my uncle holding? [Unknown location, United States]

This picture of my great uncle was probably taken in the seventies. He was a real ophiophile! I'm sorry it's so unclear, and in black and white, but I'm hoping someone might be able to ID it. I don't know for sure where it was taken, or if it's a native snake. It doesn't narrow it down much, but I know he lived in Texas, Florida, and Tennessee, though I don't know where he was for this picture. Thanks for any insight!