Data comes from ?df_county_unemployment. The choropleth is rendered with the function ?county_choropleth in the choroplethr package.
county_unemployment_choropleth(year = 2013, num_colors = 7, zoom = NULL)
The year of data to use. Must be between 1990 and 2013.
The number of colors on the map. A value of 1 will use a continuous scale. A value in [2, 9] will use that many colors.
An optional vector of states to zoom in on. Elements of this vector must exactly match the names of states as they appear in the "region" column of ?state.regions in the choroplethrMaps package.