Does anyone know where I can find an accurate polygon database of all golf courses in the us?
The 05 ESRI StreetMap lyr file contains about 7100 golf course polygons nation-wide. However this most likely is a small sample of all the courses that may exist.
Google Earth has fairly complete data set of these, it's only a viewer though. I remember a few years ago seeing a GIS job with golflink.com, might try contacting them and see if they share / sell their data sets
8852 golf courses in USA http://geodeg.com/search.php?q=golf+course&language=&country=220
I don't think every data dream can come to reality.
If there's an agency which does not have a vision to manage geo-spatial information for itself, getting such a data can be a tedious task.
You can get the textual information very easily, but finding a GIS data can be (almost) impossible.
See the Golf Directory...