[0xcde4c3db]

Many small/medium American "cities" are municipalities that are directly attached to (or even surrounded by) a larger urban area. It's basically a quirk of how local government is structured rather than anything that has to do with population or infrastructure density. For example, it's unlikely that many residents of Beverly Hills (<50K residents) think of themselves as living in a small town outside of Los Angeles.

[eli_gottlieb]

Similarly, the municipalities of Boston and Cambridge remain separated by the natural border of the Charles River, even if by nothing else at all. Cambridge and Somerville don't even have that much justification for existing as separate municipalities: you can accidentally walk across the municipal border and back again without noticing it in some places.