Boulder City, Nevada, was built as a semi-permanent town in 1931 to house 5,000 working on the Hoover Dam.

The Wikipedia entry says the city "was exceptionally rare as an example of a town fully planned under government supervision. This is unlike 19th century privately funded company town examples found in the United Kingdom, such as Port Sunlight, or in the United States, such as Pullman, Chicago."

https://en.wikipedia.org/wiki/Boulder_City,_Nevada

The thing that fascinates me about company and government towns is the rules the residents ended up having to follow. In Boulder City, no drinking, prostitution or gambling. In Saltaire, UK, no hanging washing on a line, or "Gatherings or loitering of more than eight persons in the streets".

http://www.saltairevillageexperience.co.uk/rules-for-living-...