Although Arizona is not one of the most populous states in the US, it has by far the highest state capital population in the country with close to 1.7 million people living in Phoenix, up from just under 1.5 million in 2010. Austin, Texas is a distant second with around 900,000 residents as of 2018, and Columbus, Ohio comes in third with approximately 860,000 residents.
The vast majority of state capitals have fewer than 500,000 residents. This includes the capitals of some of the largest and most populous states. For example, Florida is one of the most highly populated states, but its capital, Tallahassee, has a population of just 193,000. New York City is the largest city in the US, but New York state capital Albany has fewer than 100,000 residents.
Some of the largest states also have some of the smallest state capitals, including Cheyenne, Wyoming (65,249), Helena, Montana (32,285), and Juneau, Alaska (32,198). These numbers reflect the fact that, although these states are geographically large, they are much more remote and sparsely populated than many other areas of the United States.
Interestingly, most of the state capital population numbers have stayed relatively stable when the 2010 and 2018 census data is compared. Outside of the top ten, which all show fairly substantial population increases, quite a few state capitals show increases of only a few thousand. Little Rock, Arkansas went from 193,524 in 2010 to 199,233 in 2018, Lansing, Michigan rose from 109,563 to 113,348, and Olympia, Washington increased its population from 46,478 to 53,144.
Some state capitals, including Charleston (West Virginia), Jefferson City (Missouri), and Montpelier (Vermont) – also the smallest state capital with around 7,500 residents – saw population decreases, possibly reflecting changing demographics and opportunities within these areas in the economically challenging years of the first half of the decade.