Don says the boards were sized to fit into the boxes. Doesn't know about the draftsmanship to create the skewed hexes though.
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No you read the WIKI wrong, the US Survey distance is still the OLD, not exactly 25.4. They didn't want to mess with existing boundaries or maps. Thus the "statute" mile.
Impetus to change was invention of a physics-based standard in the 1920's, and discovering that the physical standard was shrinking by 1/10^6 a year due to stress relief in the bronze. We followed England a couple years later when the treaty signing caught up.