In the 1950's my dad grew a Black Diamond watermelon that won the regional large watermelon prize that year. Congressman Frank Boykin took it and claims to have given the watermelon to president Truman.
This is one of the ways I earned money as a teenager.(That's a familiar scene to me, even today around here)
:^) It’s a variety better suited for the south, melons in general do better with a longer growing season. This year we’re having a great year for field corn, rains a couple of times a week, blazing hot other days. You could almost build treehouses in these things.