```r
library(rnaturalearth)
usa = ne_countries(country = "United States of America") # United States borders
class(usa)
#> [1] "SpatialPolygonsDataFrame"
#> attr(,"package")
#> [1] "sp"
# alternative way of accessing the data, with raster::getData()
# getData("GADM", country = "USA", level = 0)
```