It is usually difficult or inconvenient to create US maps that include both Alaska and Hawaii in a convenient spot. All map data frames produced by this package use the Alber's Equal Area projection.
Alaska and Hawaii have been manually moved to a new location so that
their new coordinates place them to the bottom-left corner of
the map. These maps can be accessed by using the usmap function.
The function provides the ability to retrieve maps with either
state borders or county borders using the regions parameter
for convenience.
States (or counties) can be included such that all other states (or counties)
are excluded using the include parameter.
Several functions have been included to lookup the US state or county pertaining to a FIPS code.
Likewise a reverse lookup can be done where a FIPS code can be used to retrieve the associated state(s) or county(ies). This can be useful when preparing data to be merged with the map data frame.
A convenience function plot_usmap has been included which
takes similar parameters to us_map and returns a ggplot2
object. Since the output is a ggplot object, other layers can be
added such as scales, themes, and labels. Including data in the function call
will color the map according to the values in the data, creating a choropleth.
Rudis, Bob. "Moving The Earth (well, Alaska & Hawaii) With R." Blog post. Rud.is., 16 Nov. 2014. Web. 10 Aug. 2015. <https://rud.is/b/2014/11/16/moving-the-earth-well-alaska-hawaii-with-r/>.
Helpful links:
FIPS code information http://en.wikipedia.org/wiki/FIPS_county_code http://en.wikipedia.org/wiki/FIPS_state_code
US Census Shapefiles https://www.census.gov/geo/maps-data/data/tiger-cart-boundary.html
Map Features https://en.wikipedia.org/wiki/Map_projection https://en.wikipedia.org/wiki/Albers_projection https://en.wikipedia.org/wiki/Choropleth