do American houses have a TV connection in the wall or is this only for cable?

it depends most houses doesnt have any hook up at all any more

when you have cable or satelite installed they wil put one in themselves

It depends.I will preface that in the USA/Canada, that it is normal to use the F connector for cable TV, antenna, or satellite dish signals. Hence forth when I say "Cable", I don't mean the service, just the presence of a wire and//or wall jack at TV locations, leading to a location to connect to any coaxial based source service available to the house.

Modern housing developments, especially high-rise condos and such, often come pre-wired with "cable".

Sometimes that is an optional upsell by the developer.

Older houses (before the 1980s) usually don't come wired with/for a cable, which will be added after the fact as services get added to the household, or if they are up on things at build. Often in those cases, a wall jack proper isn't installed, rather the coax cable is just fed through a hole in the wall.

It varies.

Some housing developments come with every room pre-wired for cable or sat service.

The local cable company or satellite company will usually install wiring for free when you sign up.

However - there are many rural areas, farms and places in the woods where it is hugely expensive for the local cable company to dig a trench to come near or reach every home so they just dont bother. These people have to use an antenna or order Satellite service from DirectTV or DishNetwork.

A newer thing (in the last 6 years or so) is if a house has high-speed internet. Companies like AT&T UVerse or Verizon Fios have dense areas where they run fiber-optic wires near the homes and you can get TV service as well as internet on this ultra-fast network.

I assume you mean an antenna connection. My house has one. Many newer housed were not built with an antenna, however one could be added later.