us_counties: County boundaries (contemporary and historical)

In USAboundaries: Historical and Contemporary Boundaries of the United States of America

County boundaries (contemporary and historical)

Description

Get the current (2024) boundaries for U.S counties from the U.S. Census Bureau, or get historical county boundaries for dates between 30 December 1636 and 31 December 2000.

Usage

us_counties(map_date = NULL, resolution = c("low", "high"), states = NULL)

Arguments

map_date	The date of the boundaries as some object coercible to a date with as.Date(); the easiest option is a character vector following the ISO 8601 data format. If NULL (the default) the contemporary boundaries will be returned.
resolution	The resolution of the map.
states	A character vector of state or territory names or abbreviations. Only boundaries for those states/territories will be returned. If NULL, all boundaries will be returned.

Value

An sf object.

See Also

For documentation of and citation to the underlying shapefiles for contemporary data from the U.S. Census Bureau, see the census_boundaries help file in the USAboundariesData package. For documentation of and citation to the underlying shapefiles for historical data from the Atlas of Historical County Boundaries, see the ahcb_boundaries help file in the USAboundariesData package.

Examples

if (require(USAboundariesData, quietly = TRUE) && require(sf, quietly = TRUE)) {
  contemporary_us <- us_counties()
  historical_us <- us_counties("1820-07-04")
  contemporary_ne <- us_counties(
    states = c(
      "Massachusetts",
      "Vermont",
      "Maine",
      "New Hampshire",
      "Rhode Island",
      "Connecticut"
    )
  )
  historical_ne <- us_counties(
    "1803-04-28",
    states = c(
      "Massachusetts",
      "Vermont",
      "Maine",
      "New Hampshire",
      "Rhode Island",
      "Connecticut"
    ),
    resolution = "high"
  )

  plot(st_geometry(contemporary_us))
  plot(st_geometry(historical_us))
  plot(st_geometry(contemporary_ne))
  plot(st_geometry(historical_ne))
}

USAboundaries documentation built on Jan. 30, 2026, 1:07 a.m.