Final answer:
The Old Minnehaha County Jail walls were constructed using stone courses typically covered with plaster, a historic building technique evident in similar era structures.
Step-by-step explanation:
The Old Minnehaha County Jail's walls used a construction technique common in historical masonry. This involved courses of stone that were covered with a layer of plaster, sometimes painted to mimic the stone's appearance. Using similar historical examples, the stone was first laid in careful arrangement and then a thin layer of plaster might be applied over it.
An example is the twelfth- and thirteenth-century structures, which were made of stone, mortar, and plaster. A reference point for this historic masonry method is the Minoan variation, where after the initial stone and mud construction, walls were thinly coated with lime plaster, followed by fine plaster, and often accented with paint or pigment, as seen in the preservation of earth tone colors and later, red pigment on the Jelling Stones.