Atomic Boom-town

As a community, Los Alamos was atypical. The population was homogeneous; most people were in their 20s or 30s, healthy, and middle-class. Unemployment did not exist. Despite the informality of the place, it was not, as former resident Ruth Marshak remembered, a caste-less society. Employees' ranking in the Laboratory dictated their social standing as well as the quality of their housing was determined by one's position in the Laboratory.

http://www.lanl.gov/history/wartime/duringwar.shtml