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Idaho decennial census population

The official resident population count for Idaho and its 44 counties at each decennial census, as opposed to the Population Estimates Program's between-census estimates.

Figures

Decennial census population, 1870 to 2020Decennial census population, 1870 to 2020. Idaho: 14,999 in 1870, 1,839,106 in 2020.0500k1M1.5M2M19002000IdahoPeopleDecennial census population, 1870 to 2020Decennial census population, 1870 to 2020. Idaho: 14,999 in 1870, 1,839,106 in 2020.0500k1M1.5M2M190019502000IdahoPeopleDecennial census population, 1870 to 2020Decennial census population, 1870 to 2020. Idaho: 14,999 in 1870, 1,839,106 in 2020.0500k1M1.5M2M190019502000IdahoPeople

Source: U.S. Census Bureau, Decennial Census population counts. Data period 2020. Published .

MeasureValuePeriod
Decennial census population20201,839,1062020

Pages built on this dataset

Publisher

Organization
U.S. Census Bureau
Publisher’s dataset
Decennial Census population counts
File or API used
https://www2.census.gov/library/publications/2003/dec/phc-3-14.pdf
Methodology
https://www.census.gov/programs-surveys/decennial-census/about/history.html

Coverage

Geography
Idaho and its 44 counties
Time coverage
1870-2020
Update frequency
Decennial
Published
March 26, 2026
Retrieved
September 8, 2026
License of the records
Public domain. U.S. federal government work.
Rows
324 observations, 1870-2020

Measures

MeasureWhat it measuresUnit
Decennial census populationResident population as counted at the decennial census.people

Caveats

  • State totals for 1870-2000 are from the Census Bureau's 2003 report "Population and Housing Unit Counts, Idaho: 2000" (report PHC-3-14); totals for 2010 and 2020 are from the 2020 Census apportionment product (2026).
  • County totals cover 1960-2020 only; no source used here tabulates all 44 counties for an earlier census.
  • 2020 county values are the Population Estimates Program's postcensal estimates base, not the original 2020 Census redistricting tabulation.
  • Some county and state figures are the Census Bureau's later revision of the originally published census count, not the original figure.

Where sources disagree

  • Decennial census population, Idaho, 1970: U.S. Census Bureau, Population of States and Counties of the United States: 1790-1990 (March 1996) publishes 712,567. This dataset uses the 2003 report's 713,015. The 1996 compilation, and the 2020 Census apportionment product's historical table, both give 712,567 for the same census.
  • Decennial census population, Idaho, 1980: U.S. Census Bureau, Population of States and Counties of the United States: 1790-1990 (March 1996) publishes 943,935. This dataset uses the 2003 report's 944,127. The 1996 compilation, and the 2020 Census apportionment product's historical table, both give 943,935 for the same census.
  • Decennial census population, Idaho, 1990: U.S. Census Bureau, Population of States and Counties of the United States: 1790-1990 (March 1996) publishes 1,006,749. This dataset uses the 2003 report's 1,006,734, itself marked as a post-hoc revision in that table. The 1996 compilation, and the 2020 Census apportionment product's historical table, both give 1,006,749 for the same census.
  • Decennial census population, Bonneville County, 1970: U.S. Census Bureau, Population of States and Counties of the United States: 1790-1990 (March 1996) publishes 51,250. This dataset uses the 2003 report's Table 2 figure of 52,457 for Bonneville County. The 1996 compilation gives 51,250 for the same census; this is one of the pre-1960 figures in that scanned report this dataset otherwise chose not to rely on.

How to cite

Understand Idaho, “Decennial Census population counts”, compiled from U.S. Census Bureau, Decennial Census population counts. Retrieved September 8, 2026. https://understandidaho.com/data/census-decennial/.

Cite U.S. Census Bureau directly for the figures themselves.

This page was last updated .