[ButThreeLeftsDo]

Prinsburg, Minnesota.

Population: 497

Never heard of it.

[Stosh]

Graymont, Illinois; unincorporated; population under 300 - there might be some point to the study if they put a (sensible) lower limit to what they’d consider a “city”.

[Vigilanteman]

A big metropolis compared to Allensville, Pennsylvania, which I can't even find on the blown-up county map.