James J. Hill. He was a rich railroad guy back in the day. He funded the building of the iconic Stone Arch Bridge in Minneapolis.
That's what the people of Minneapolis thought. Why is he building this crazy expensive bridge? It seems pointless. So they dubbed it "Hill's Folly" (see where this is going?).
It wasn't until the bridge was finished that the value of the bridge was seen and it, in part, helped Minneapolis grow into the amazing city it is today. Take a look at the logo...notice a certain MPLS bridge? Folly also means "a sense of foolishness", so yeah...that fits perfectly!