Get Census Data for All Counties in a State

Downloads and processes U.S. Census Bureau population estimates for all counties in a specified state, organized by age groups. Returns a list where each element contains the data for one county.

Usage

getAllCountiesData(
  state_fips,
  year = 2025,
  age_groups = NULL,
  age_groups_by_county = NULL,
  by_sex = FALSE,
  csv_path = NULL,
  cache_dir = NULL,
  verbose = FALSE
)

Arguments

state_fips

Two-digit FIPS code for the state (e.g., "49" for Utah)

year

Census estimate year: 2020-2025 for July 1 estimates, or 2020.1 for April 1, 2020 base

age_groups

Vector of age limits for grouping (e.g., c(0, 5, 18, 65)). Default NULL returns single-year ages 0-85+. Ignored if age_groups_by_county is provided.

age_groups_by_county

Optional named list where each element is a vector of age limits for a specific county. Names should match county names (with or without " County" suffix). When provided, county-specific age groups will be used, overriding the age_groups parameter. Example: list("Salt Lake" = c(0, 5, 18, 65), "Utah" = c(0, 5, 11, 18, 65))

by_sex

Logical, if TRUE returns separate male/female groups

csv_path

Optional path to a previously downloaded census CSV file. If provided, data will be read from this file instead of downloading. Use cache_dir for automatic caching.

cache_dir

Optional directory path for caching downloaded census files. If provided, the function will check for an existing cached file and use it, or download and save a new one. Default is NULL (no caching). Use "." for current directory or specify a custom path like "~/census_cache"

verbose

Logical, if TRUE prints messages about data loading and processing. Default is FALSE.

Value

A named list where each element corresponds to one county. Each element is a list containing the same structure as returned by getCensusData():

county

County name

state

State name

year

Census year

total_pop

Total population

age_pops

Vector of populations by age group

age_labels

Labels for each age group

sex_labels

If by_sex=TRUE, labels indicating sex

data

Full filtered data frame

Examples

# Use the included example data for Utah
# \donttest{
utah_all <- getAllCountiesData(
  state_fips = "49",
  year = 2025,
  csv_path = getCensusDataPath()
)

# Access specific counties
utah_all[["Salt Lake County, Utah"]]
#> NULL
utah_all[["Utah County, Utah"]]
#> NULL

# Get with age groups
utah_grouped <- getAllCountiesData(
  state_fips = "49",
  year = 2025,
  age_groups = c(0, 18, 65),
  csv_path = getCensusDataPath()
)

# Get with county-specific age groups
county_ages <- list(
  "Salt Lake" = c(0, 5, 18, 65),
  "Utah" = c(0, 5, 11, 18, 65)
)
utah_custom <- getAllCountiesData(
  state_fips = "49",
  year = 2025,
  age_groups_by_county = county_ages,
  csv_path = getCensusDataPath()
)

# Download from web (requires internet)
utah_web <- getAllCountiesData(
  state_fips = "49",
  year = 2025
)
# }