it's an automatic, instinctive behavior that precedes the development of citystates. placing waystones is a navigational tool and it is a way to stockpile building materials if a settlement develops. navigational markers that build up enough density inevitably invite development. white people can't help themselves. some other races do it, too - notably egyptians, somalis, japanese, peruvians, and polynesians, but it's only higher races (relatively higher in the case of somalis, as they are the dumbest white offshoot - they are actually genetically closer to whites than blacks, unfortunately) that have an inherent instinct to support the development of societies.
United States