Seeking polygon shapefile of countries, states and islands?

As often happens, the hardest part of GIS is to come up with clean shapefile with an attribute table.

I need to create a choropleth map, but all I have is this:

Domicile,Captives
New Zealand,24
Vanuatu,7
Hong Kong,3
Labuan,38
Micronesia,14
Singapore,64
British Columbia,21
Anguilla,252

As you can see, some of them are countries, some are US states and there are islands too.

The way I think of doing this is to first look for a world polygon shapefile of countries, then a shapefile of states and then look manually for what is left.

Is there a shapefile that contains everything?

Answer

You can use the site Global Administrative Area. There, you can find surfacic shapefile for each country. Each country is divided according to its administrative divisions (ex: provinces). You can also download a polygon for the entire world.

http://www.gadm.org