Marshall County Demographics

A map of Marshall County's Population by Race

Race	2024 Pop	2020 Pop	2024 %	2020 %
White	26,461	27,438	66.0%	68.4%
Hispanic	9,875	9,140	24.6%	22.8%
Asian	1,631	1,514	4.1%	3.8%
Multiracial	1,279	983	3.2%	2.5%
Black	624	785	1.6%	2.0%
Native American/Other	244	245	0.6%	0.6%

Marshall County, Iowa has an estimated population of 40,114, a less than 1% change from the 40,105 recorded in the 2020 Census. The population is 66.0% White, 24.6% Hispanic, 4.1% Asian, 3.2% Multiracial, 1.6% Black, and 0.6% Native American/Other. This demographic dot map shows the population of Marshall County, with one dot drawn for each person counted by the Census, color-coded by race.

Marshall has become more racially diverse since the 2020 Census. It is considerably more diverse than Iowa overall. Demographers use a diversity index to measure the probability that two randomly selected individuals belong to different racial or ethnic groups. In Marshall County, that probability was 47.8% in 2020 and 50.1% in the most recent ACS estimates.

Marshall County is ranked the 15th most populous county in Iowa, out of 99 counties. Marshall County was ranked the 15th most populous county in the 2020 Census.

Marshall County's White Population

26,461 residents of Marshall County, or 66.0% of the population, identify as White. The share of White residents in Marshall County is significantly lower than in Iowa overall, where 82.3% of the population is White. Marshall County ranks 96th statewide in terms of White residents as a share of the population, out of 99 counties.

Since the 2020 Census, Marshall County's White population has declined by an estimated 3.6%. White residents' share of Marshall County's population has decreased from 68.4% to 66.0%.

Marshall County is less White than neighboring Jasper County (90.8% White), Grundy County (94.9% White), Hardin County (90.1% White), Story County (81% White), and Tama County (78.4% White).

Marshall County's Black Population

624 residents of Marshall County, or 1.6% of the population, identify as Black. The share of Black residents in Marshall County is slightly lower than in Iowa overall, where 3.8% of the population is Black. Marshall County ranks 25th statewide in terms of Black residents as a share of the population, out of 99 counties.

Since the 2020 Census, Marshall County's Black population has declined by an estimated 20.5%. Black residents' share of Marshall County's population has remained roughly unchanged at 1.6%.

Marshall County is more Black than neighboring Jasper County (1.5% Black), Grundy County (0.6% Black), Hardin County (1.1% Black), and Tama County (0.9% Black). Marshall County is less Black than neighboring Story County (2.7% Black).

Marshall County's Asian Population

1,631 residents of Marshall County, or 4.1% of the population, identify as Asian. The share of Asian residents in Marshall County is comparable to the share in Iowa overall, where 2.5% of the population is Asian. Marshall County ranks 6th statewide in terms of Asian residents as a share of the population, out of 99 counties.

Since the 2020 Census, Marshall County's Asian population has grown by an estimated 7.7%. Asian residents' share of Marshall County's population has remained roughly unchanged at 4.1%.

Marshall County is more Asian than neighboring Jasper County (0.7% Asian), Grundy County (0.5% Asian), Hardin County (0.8% Asian), and Tama County (0.7% Asian). Marshall County is less Asian than neighboring Story County (6.6% Asian).

Marshall County's Hispanic Population

9,875 residents of Marshall County, or 24.6% of the population, identify as Hispanic. The share of Hispanic residents in Marshall County is significantly higher than in Iowa overall, where 7.3% of the population is Hispanic. Marshall County ranks 3rd statewide in terms of Hispanic residents as a share of the population, out of 99 counties.

Since the 2020 Census, Marshall County's Hispanic population has grown by an estimated 8.0%. Hispanic residents' share of Marshall County's population has increased from 22.8% to 24.6%.

Marshall County is more Hispanic than neighboring Jasper County (3.1% Hispanic), Grundy County (1.8% Hispanic), Hardin County (5.5% Hispanic), Story County (5.2% Hispanic), and Tama County (11.7% Hispanic).

Marshall County's Native American/Other Population

244 residents of Marshall County, or 0.6% of the population, identify as American Indian/Alaska Native/Native Hawaiian/Pacific Islander/Other. The share of Native American/Other residents in Marshall County is comparable to the share in Iowa overall, where 0.6% of the population is Native American/Other. Marshall County ranks 24th statewide in terms of Native American/Other residents as a share of the population, out of 99 counties.

Since the 2020 Census, Marshall County's Native American/Other population has remained roughly the same. Native American/Other residents' share of Marshall County's population has remained roughly unchanged at 0.6%.

Marshall County is more Native American/Other than neighboring Jasper County (0.3% Native American/Other), Hardin County (0.4% Native American/Other), and Story County (0.5% Native American/Other). Marshall County is less Native American/Other than neighboring Grundy County (1.2% Native American/Other), and Tama County (5.4% Native American/Other).

Marshall County's Multiracial Population

1,279 residents of Marshall County, or 3.2% of the population, identify as Multiracial. The share of Multiracial residents in Marshall County is comparable to the share in Iowa overall, where 3.5% of the population is Multiracial. Marshall County ranks 52nd statewide in terms of Multiracial residents as a share of the population, out of 99 counties.

Since the 2020 Census, Marshall County's Multiracial population has grown by an estimated 30.1%. Multiracial residents' share of Marshall County's population has increased from 2.5% to 3.2%.

Marshall County is more Multiracial than neighboring Grundy County (1.1% Multiracial), Hardin County (2.1% Multiracial), and Tama County (2.9% Multiracial). Marshall County is less Multiracial than neighboring Jasper County (3.6% Multiracial), and Story County (4% Multiracial).

Sources: Most recent population estimates are from the 2020-2024 American Community Survey 5-Year Estimates. 2020 population counts and map data are from 2020 Census State Redistricting Data. Geographic data are from Census TIGER/Line Shapefiles.