During the 50's we mostly had our hay baled in "square" bales. Square in quotes because they weren't really square--they were close to being square in cross section but about twice as long as they were wide. Think bricks, but larger, and scratchier.
Extension talks about stacking bales as an almost lost skill. Actually, it's the skill of arranging loose hay on a jay wagon so that it stays in place that's lost. That's a skill I never mastered.