Census data released Tuesday shows Illinois' population increased 3.3 percent from 2000 to 2010, gaining 445,087 residents during the past decade.
Despite gaining nearly half a million residents, 61 of Illinois' 102 counties recorded population losses since the 2000 census. Even with the majority of counties losing population, Illinois still ranks as fifth most populous state in the U.S. with 12,864,380 residents.
In Southern Illinois, 12 of the 17 southernmost counties recorded a decline in population; only Williamson, Jackson, Franklin, Massac and Pope counties recorded population increases.
The population of the 17 southernmost counties in 2000 was 386,611; the 2010 count puts the region at 383,421 - a loss of 3,190 residents.
In Williamson, Marion
The 2010 census shows Williamson County saw the largest gain of population in Southern Illinois. The county population is 66,357; up more than 5,000 residents from the 61,296 recorded in 2000.
Williamson County Commissioner Brent Gentry said there are several factors that helped bolster the county's population. He said he believes a major factor that led to the increase is the county's business-friendly climate.
Gentry said the county's relationship with municipalities helps foster growth because both entities work toward a common goal. He said the county dedicates a lot of energy into bringing new jobs, businesses and families to the area.
Geographically, Gentry said Williamson County is in a prime location in Southern Illinois that will help it continue to expand. He said the county's proximity to Southern Illinois University and John A. Logan College, highly rated school districts, as well as the STAR bond district have the county in a position to grow dramatically.
"We're very blessed to live in Williamson County because of our growth," he said. "I predict we'll, in three to five years, hit 70,000 in population."
Williamson County's most populous municipality, Marion, saw an increase in population of more than 1,100 people, up from 16,035 residents during the 2000 count. Marion's population in the 2010 census was 17,193.
Marion Mayor Bob Butler said he wasn't surprised to see the city's population increase, but was surprised the county numbers had increased as they had. Butler said the increase in population is important to the city because it helps determine motor fuel tax, state income tax and eligibility for certain grants.
Butler agreed with Gentry, saying city's geographic location and business climate have helped draw people.
"We attribute our growth to the overall friendly business climate that we foster and aggressively work on."
He, too, said he believes the city and county will continue to grow and expects the STAR bond project to be a catalyst for growth.
Modest gain in Jackson
Jackson County saw a modest gain in population. The 2010 numbers put the county at 60,218 residents, up from 59,612 in 2000.
John S. Rendleman, Jackson County board member and census coordinator, said although the gains aren't significant population-wise, the county will use the census figures to redraw county board districts and voting precincts based on population shifts.
"Because the county population gain was very modest it probably won't mean too much shift in political boundaries," said Rendleman.
For most, slight losses
The majority of Southern Illinois counties saw a population loss in the past decade.
Union County's population declined 485 residents, down to 17,808 in 2010 from 18,293 in 2000.
Union County Commissioner Don Denny said Union County is one of the smaller counties in Southern Illinois, but doesn't expect the small population shift to affect the county drastically.
Denny said he couldn't attribute the decrease in population to any one issue, and was surprised to see the decline based of the number of building permits issued by the county. He said one possible cause to the drop in population could have to do with the young people in the county.
"We do lose a lot of kids who graduate high school and go to college," Denny said. "If we don't have the jobs it's hard for them to get back into the county."
Perry County Clerk Kevin Kern said the county population is typically steady.
"If you look at the population of our county from a historic perspective our county population has remained steady since 1900."
Perry County's population declined by 744 residents, down to 22,350 in 2010 from 23,094 in 2000.
Kern said looking at the 2010 census figures, six of the county's major municipalities lost population to some degree. He said Pinckneyville was the only municipality to see an increase in population. Kern said between the 1990 and 2000 censuses, Pinckneyville's population increased due to the Pinckneyville Correctional Center being built.
Pinckneyville's recorded population in the 2010 census was 5,648 - up 184 residents from the 5,464 recorded in the 2000 census. Kern said it is unclear whether the population increase can be attributed to more inmates at the Pinckneyville Correctional Center or whether more people are moving into the city.
"I think our population is most emblematic of a lot of places in downstate Illinois," Kern said.
He said the figures won't greatly affect the county budget, but could change the county's grant eligibility and state funding.
"Anytime your numbers go down that has an affect on the money you get," Kern said. "I think we're discouraged we're down a little bit, but we're holding our own."