Converting a “map” object to a “SpatialPolygon” object

Question

I am guessing there is a simple solution to the problem I have been having, but I am having some trouble.

I am trying to convert the following map objec

Answer 1

Polygons have surface (area), therefore the key argument is fill = TRUE in

usa <- map('state', fill = TRUE)

Changing the argument value to TRUE stops the error message.