According to 2020 decennial census data of the U.S. Census Bureau, the nation’s population increased from 328.3 million in 2019 to 331.4 million in 2020 — adding about 3.1 million new residents. The U.S. population increased 7.4 percent between 2010 and 2020.
New Jersey had the fastest growth rate with a 4.5 percent growth rate over the past year followed by New York (3.8%). Rounding out the list of most rapidly growing states are Rhode Island (3.7%), Vermont (3.0%), Hawaii (2.8%), and Idaho (2.8%). Population decreased in several states, most prominently in Arizona (-1.9%), South Carolina (-0.8%), North Carolina (-0.6%), Mississippi (-0.6%), Arkansas (-0.3%), West Virginia (-0.1%), and South Dakota (-0.1%).
The most populous states in the U.S. are California (39.5 million), Texas (29.1 million), Florida (21.5 million), New York (20.2 million), Pennsylvania (13.0 million), and Illinois (12.8 million). Top five states with the largest one-year, 2019 to 2020, population gains were New York (+738,118), New Jersey (+397,736), Pennsylvania (+203,817), Texas (+158,711), and Illinois (+145,491). Top five states with the largest one-year, 2019 to 2020, population losses included Arizona (-140,341), North Carolina (-61,996), South Carolina (-39,277), Mississippi (-16,948), and Arkansas (-9,461).
Missouri ranked 19th by population size in 2020 with 6,154,913 residents. The state gained 14,438 new residents between 2019 and 2020. Neighboring Illinois added 145,491 residents; neighboring Arkansas lost 9,461 residents. Nebraska and Tennessee had the largest one-year percentage increases among states that surround Missouri: 1.5 and 1.2 percent, respectively. Illinois (1.1%), Iowa (1.0%), Kansas (0.9%), and Kentucky (0.7%) as well as Missouri (0.2%) grew in population whereas Oklahoma (-0.03%) and Arkansas (-0.3%) lost population when compared to 2019.
In 2020, St. Louis County was the largest county in Missouri with over one million (1,004,125) residents followed by Jackson County with 717,204 residents, St. Charles County with 405,262 residents, St. Louis City with 301,578 residents, and Greene County with 298,915 residents. The county with the smallest population in Missouri was Worth County with 1,973 residents.
Missouri counties with the largest one year (2019 to 2020) increase in population include Jackson County with 12,854 population growth, St. Louis County with 8,658 population growth, Greene County with 5,416 population growth, and St. Charles County with 3,637 population growth. Greatest loss of population between 2019 and 2020 occurred in Camden County with a population decline of 3,466 and Ripley County with a 2,664 population decline.
The following dashboard is based on the U.S. Census Bureau’s Decennial Census data for 2020 and population estimates based on 2010 Census for intermediate years. It can be used to find information about 2020 population and population changes between 2010, 2015, and 2020 for U.S. states and Missouri counties by hovering over each geography. A file containing the population data from 2010 to 2020 for U.S. states and Missouri counties can be downloaded as an Excel Spreadsheet by clicking here.
- U.S. Census Bureau’s Decennial Census data for 2010 and 2020 population.
- U.S. Census Bureau’s Population and Housing Unit Estimates Datasets for other years.