This story comes from my dad and grandfather of early days around Dodge City, Kansas. Due to the farming methods employed and the breaking out of vast tracts of land with the plow, the rabbit populations exploded. Even when I was a youngster I recall seeing hundreds of rabbits in some areas still.
I think the use of summer fallow farming methods may have made a difference too but this is about the hunts and not the cause. In any case there were literally millions of rabbits roaming about and eating all the farm crops.
So area farmers and towns people would announce a Jack Rabbit Roundup on a Saturday and thousands of people would gather at some predetermined spot and surround a large tract of land inhabited by rabbits. Slowly they would walk toward one another in a vast circle closing with each step to a tighter surround. In the center of that effort they would erect a tall fenced enclosure and the rabbits would run toward the center until trapped in the pen.
There the butchering began. It was a horrible sight of mutilation and death as men would club the poor rabbits to death as guns were not safe with so many people in close proximity to one another. The rabbits would scream and squeal with terrible fright and if you have ever heard one in pain you never forget it.
My dad said it was too much for him and he never went again although it was a necessary evil to rid them of the vermin or they would not have a crop.
Changes in farming practices and sprays used on the fields probably ended the rabbit plagues and you consider yourself lucky to see ONE in an entire hunting season in Kansas.