When analyzing population shifts in the U.S., we tend to focus on larger trends of how many and where. For example, according to the 2020 census, all regions of the country recorded population growth over the past decade, which mirrored the nationwide trend of population growth — 7.4% in the decade. Yet the biggest gains were in the South and West, where growth hit 10.2% and 9.2%, respectively. The Midwest registered the lowest growth, at 3.1%.
Population shifts over the past nearly century and half, from 1880 to 2020, track those recent tilts to the Southern and Western states. Arizona had the highest population growth over that time, recording a nearly 177-fold jump in population to reach 7.2 million. Washington state came in a distant second with a nearly 103-fold increase to 7.7 million. Florida’s population grew by roughly 80 fold to 21.5 million.
It’s also interesting to see where people are relocating to within their home state. Most people stay close to home rather than pulling up stakes and migrating to another part of the country, so chances are they’re not going very far. People also move to places where there is a major city for better job prospects. According to a Move.org survey of 1,000 people who relocated in 2022, 43% of people moved within the same city, and 35% within the same state. (This is the population growth since 2000 in America’s largest cities.)
To determine how the population of every state has changed in the last 140 years, 24/7 Wall St. reviewed centers of population data from 1880 to 2020 from the U.S. Census Bureau. The Census explains that the center of population is a balance point — the point at which an imaginary flat scale of a state’s map would balance if every state resident had equal weight. Put another way, it is the average location where people within a state live.
In Arizona, the center of population shifted nearly 27 miles northwest to Maricopa County, the state’s most populous county and the fourth most populous in the nation. The county includes the state capital, Phoenix, and its suburb, Tempe.
What made Arizona such a magnet for new residents is the invention of air conditioning in the past century, according to James N. Gregory, a history professor at the University of Washington. He told the Anchorage Daily News that air conditioning made the state’s hot dry climate more bearable.
California’s center of population shift was second largest, at 205 miles southeast. Located 130 miles north of Los Angeles, Kern County is now the center of population in the Golden State. It’s the 11th most populated county in the state, with Bakersfield as its county seat.
Nevada had the largest shift in its center of population since 1880, shifting nearly 210 miles southeast to Nye County. Florida had the third largest center of population shift, 164 miles southeast to Polk County. At the other end of the spectrum, Rhode Island had the smallest shift, just 1.2 miles.
Vermont and Iowa had the smallest population growth from 1880 to 2020. Vermont’s population inched up a mere 1.9-fold to 643,077. Its center of population as of 2020, which shifted only 7 miles since 1880, was Washington County. The county includes the small town of Waitsfield, about 20 miles from the state capital of Montpelier. (This state had the biggest population drop in the past 10 years.)
Iowa didn’t fare much better with a 2-fold population increase to 3.2 million. Its center of population, which also shifted just 7 miles, is Marshall County, with Melbourne, a rural town with less than 800 residents, the closest to the center.