This article is devoted to an investigation of the forms of human capital that characterize cities at different levels of the US urban hierarchy. Basic data on human capital are drawn from the O*Net information system. A first analytical exercise shows that for the USA as a whole, occupations marked by broadly cognitive human capital assets gained in employment over the period from 2000 to 2006, whereas employment in occupations marked by broadly physical human capital assets declined. These same types of assets bear a distinctive relationship to the urban hierarchy, with the former being concentrated in large metropolitan areas, and the latter in small. Changes in these assets over the 2000–2006 period are then examined. Surprisingly, cognitive assets increased most strongly in small metropolitan areas and physical assets increased most strongly in large. Further analysis of these findings suggests that they are quite consistent with a wider view of the contemporary urban economy. In particular, in large metropolitan areas, expanding human capital assets focused on the physical abilities of workers has nothing to do with the ‘old’ economy as such, but represents a major—and hitherto much overlooked—segment of the labor force whose functions revolve around the maintenance of the material and social fabric of life in those areas.