tigris (version 1.6)

congressional_districts: Download a congressional districts shapefile into R

Description

Description from the US Census Bureau (see link for source): Congressional districts are the 435 areas from which members are elected to the U.S. House of Representatives. After the apportionment of congressional seats among the states, which is based on decennial census population counts, each state with multiple seats is responsible for establishing congressional districts for the purpose of electing representatives. Each congressional district is to be as equal in population to all other congressional districts in a state as practicable. The boundaries and numbers shown for the congressional districts are those specified in the state laws or court orders establishing the districts within each state.

Usage

congressional_districts(
  state = NULL,
  cb = FALSE,
  resolution = "500k",
  year = NULL,
  ...
)

Arguments

state

The two-digit FIPS code (string) of the state you want, or a vector of codes if you want multiple states. Can also be state name or state abbreviation. If NULL (the default), returns the entire United States.

cb

If cb is set to TRUE, download a generalized (1:500k) cartographic boundary file. Defaults to FALSE (the most detailed TIGER/Line file).

resolution

The resolution of the cartographic boundary file (if cb == TRUE). Defaults to '500k'; options include '5m' (1:5 million) and '20m' (1:20 million).

year

the data year (defaults to 2020).

...

arguments to be passed to the underlying `load_tiger` function, which is not exported. Options include class, which can be set to "sf" (the default) or "sp" to request sf or sp class objects, and refresh, which specifies whether or not to re-download shapefiles (defaults to FALSE).

Details

Congressional districts for the 108th through 112th sessions were established by the states based on the result of the 2000 Census. Congressional districts for the 113th through 116th sessions were established by the states based on the result of the 2010 Census. Boundaries are effective until January of odd number years (for example, January 2015, January 2017, etc.), unless a state initiative or court ordered redistricting requires a change. All states established new congressional districts in 2011-2012, with the exception of the seven single member states (Alaska, Delaware, Montana, North Dakota, South Dakota, Vermont, and Wyoming).

The current default in tigris reflects boundaries for the 116th Congress, which is available as of February 2021 for years 2018 through 2021. Older congressional district boundaries back to 2011 can be obtained by supplying the appropriate year.

See Also

https://www.census.gov/programs-surveys/geography/guidance/geo-areas/congressional-dist.html

Other legislative district functions: state_legislative_districts(), voting_districts()

Examples

# NOT RUN {
library(tigris)
library(leaflet)

cd116 <- congressional_districts(cb = TRUE, resolution = '20m')

leaflet(cd116) %>%
   addTiles() %>%
   addPolygons()
# }