Answer: Circuses

In the late 19th century, the heyday of the big top circus, newspapers began to describe the massive circus entourages as armies. They arrived efficiently in massive numbers, unpacked quickly, built an entire temporary town around themselves, and just as quickly, they packed up and vanished into the night to reappear a state over, ready to entertain a whole new audience.

While the motivation might have been different, describing the whole affair as moving an army wasn’t far off. In fact, it wasn’t long before the U.S. War Department realized that the major circuses were incredibly efficient at moving their “troops”. So efficient, in fact, that starting in the 1890s, they began sending army officers to embed in the field, so to speak, with circuses in order to study their methods and pinpoint the key details that made them as efficient as they were.

Overall, the War Department was very impressed with how smoothly the circuses could unpack, organize, and repack. General Leonard Wood observed that “the great American army machine” would benefit greatly from copying the mechanisms of “the great American circus machine”.