Create a simple features data frame for US counties.
The full resolution file will be named "USCensusCounties.rda". In addition, "_05", _02" and "_01" versions of the file will be created that that are simplified to 5%, 2% and 1%. Simplified versions will greatly improve the speed of both searching and plotting.
convertUSCensusCounties()Name of the datasetName being created.
A US county borders shapefile is downloaded and converted to a simple features data frame with additional columns of data. The resulting file will be created in the spatial data directory which is set with setSpatialDataDir.
The source data is from 2021.
From the source documentation:
The primary legal divisions of most states are termed counties. In Louisiana, these divisions are known as parishes. In Alaska, which has no counties, the equivalent entities are the organized boroughs, city and boroughs, municipalities, and for the unorganized area, census areas. The latter are delineated cooperatively for statistical purposes by the State of Alaska and the Census Bureau. In four states (Maryland, Missouri, Nevada, and Virginia), there are one or more incorporated places that are independent of any county organization and thus constitute primary divisions of their states. These incorporated places are known as independent cities and are treated as equivalent entities for purposes of data presentation. The District of Columbia and Guam have no primary divisions, and each area is considered an equivalent entity for purposes of data presentation. The Census Bureau treats the following entities as equivalents of counties for purposes of data presentation: Municipios in Puerto Rico, Districts and Islands in American Samoa, Municipalities in the Commonwealth of the Northern Mariana Islands, and Islands in the U.S. Virgin Islands. The entire area of the United States, Puerto Rico, and the Island Areas is covered by counties or equivalent entities.
You can join this file with table data downloaded from American FactFinder by using the AFFGEOID field in the cartographic boundary file.