Sewage systems, fresh water to every house, electricity to every house, hut, and apartment, food available ... transportation. Roads (er, wait, them were roman inventions that the scots improved on ...)
I’m not claiming that Americans invented paved roads, but everyone should be able to make them by now. As P.J. said, a few loads of gravel, some sand, and an ox (or the wife and kids) pulling a grader.