Where in the United States do middle-class families live in condominiums or apartments?

Most middle-income families in the United States live in detached dwellings. In which cities or towns in the US is it common for families to live in condominiums or apartments? I am asking specifically with regard to families with children. Most American couples tend to move to a suburb and leave the city once their children are of school-age.

Public Comments

1. uhhhhh? Pretty much every city, even in the "higher class" suburbs ( if that's what you want to call them) have apartments and condos and there are such things as luxury apartments and condos, so I feel that's a huge stereotype, but that's besides the point, they are everywhere...so where have you been?
2. I live in NC, and most of the metro areas are town houses. They are the size of small to medium houses mostly, but some are larger. Usually 4 or 5 in one building but sometimes only 2 or 3. Many of them cost just as much if not more than detached dwellings and are inhabited by middle, and upper middle class.
3. Condos and apartments are all over the place. They are becoming more popular since many people don't want to bother with the burden of ownership. I had a house and land for two years and now I am back to renting a duplex. You wouldn't believe how much easier that made my life.