Sangamon County, Illinois

Sangamon County is a county in Illinois, United States, centred on the state capital, Springfield. It had a population of 196,343 at the 2020 census and covers 868 square miles (2,250 km2) of land plus 8.7 square miles (23 km2) of water, centred near 39°46′N 89°40′W.

Springfield is the county seat, and its postal code is 62701. The county has 4 cities, 23 villages and dozens of unincorporated communities spread across 26 civil townships, all in the Central time zone.

Towns & Villages in Sangamon County

Sangamon County has 27 incorporated municipalities — 4 cities and 23 villages — plus a long list of unincorporated crossroads and subdivisions, mostly clustered around Springfield in Capital Township. The table below marks incorporated places by type; unincorporated communities are listed as “Unincorp.” with population and ZIP left blank where no separate figure is tracked.

A small number of names carried over from older gazetteers — Andrew, Archer, Bando, Barclay, Barr, Bates, Beamington, Berry, Bissell, Breckenridge, Browns Crossing, Buckhart, Cascade, Cimic, Claysville, Cody, Coleman, Commanche Village, Compro, Ellis, Green Acres, Hawthorne Place, Haynes, Huffaker, Iles, Irwins Park, Jess, Keys, Knapp, Knollwood, Mildred, North Wind, Pasfield, Pawnee Junction, Peabody, Prouty, Richland, Riddle Hill, Ridgely, Saunders, Shale Bluff, Southlawn, Starne, Streadle, Tower Heights, Toronto, Van Wood, West Grand Place and Zenobia — are small platted subdivisions or rural crossroads inside Capital and the surrounding townships; none carries a separate census count or ZIP, so they are omitted from the table rather than given guessed figures.

Townships

Salisbury Township was dissolved and absorbed into neighboring townships; its name survives only as a rural place name, not a current civil township.

ZIP Codes

• 62701 — Springfield (downtown/central)
• 62702, 62703, 62704, 62707, 62711, 62712 — Springfield (other zones)
• 62629 — Chatham
• 62684 — Sherman
• 62615 — Auburn
• 62561 — Riverton
• 62563 — Rochester
• 62558 — Pawnee
• 62670 — New Berlin
• 62677 — Pleasant Plains
• 62693 — Williamsville
• 62520 — Dawson
• 62530 — Divernon
• 62539 — Illiopolis
• 62661 — Loami
• 62545 — Mechanicsburg
• 62625 — Cantrall
• 62515 — Buffalo
• 62536 — Glenarm
• 62689 — Thayer (PO box only)

Small villages such as Berlin, Curran, Southern View, Jerome, Grandview and Spaulding are served by a nearby town’s ZIP code rather than their own.

Geography

Sangamon County sits on the till plains of central Illinois, drained by the Sangamon River, which crosses the northern half of the county, and by its tributary Lick Creek. Lake Springfield, a large man-made reservoir on the south side of Springfield, supplies the city’s water and cooling for its power plant. The land is mostly flat to gently rolling former prairie, now a mix of row-crop farmland and suburban development around the capital.

Sangamon County borders Menard County to the north, Logan County to the northeast, Macon County to the east, Christian County to the southeast, Montgomery County to the south, Macoupin County to the southwest, Morgan County to the west and Cass County to the northwest. Part of Virden, in the southwest corner of the county, spills into Macoupin County across the shared line.

Demographics

Sangamon County had 196,343 residents at the 2020 census, giving a density of about 226 people per square mile. Springfield, the county seat, is by far the largest place with 114,394 residents; Chatham, a fast-growing suburb south of the capital, is the largest of the smaller municipalities at 13,714. Illinois state government employment has historically kept household income here close to the statewide norm; countywide median household income runs somewhat below the Illinois median of $80,306, reflecting the mix of state workers, university staff and rural households outside Springfield.

Economy & Local Life

Being the seat of Illinois government, Sangamon County’s economy centers on state agencies headquartered in Springfield, alongside two major health systems, HSHS St. John’s Hospital and Springfield Memorial Hospital, and the associated Southern Illinois University School of Medicine. Higher education is anchored by the University of Illinois Springfield and Lincoln Land Community College. Chatham and Sherman have grown as bedroom suburbs, while the rural townships remain corn and soybean country. The Illinois State Fair, held every August at the state fairgrounds in Springfield, is the county’s largest annual event.

History

Sangamon County was organized on January 30, 1821, from parts of Bond and Madison counties, and named for the Sangamon River, whose name comes from a Potawatomi or Illini word traditionally translated as referring to a place where there is plenty to eat, though the exact etymology is debated by linguists. Abraham Lincoln moved to New Salem, in what is now Menard County, in 1831 and settled in Springfield in 1837, practicing law and serving in the state legislature there before his 1860 election as president; his home and tomb remain in Springfield. The county has been the seat of Illinois state government since Springfield became the capital in 1839.

Getting There

Interstate 55 crosses the county north–south and Interstate 72 crosses it east–west, meeting on Springfield’s east side; US 36 and several state routes, including IL 4, 29, 54 and 97, radiate from the capital.

• Decatur — 40 miles east
• Jacksonville — 35 miles west
• Bloomington — 65 miles northeast
• St. Louis, Missouri — 100 miles southwest

Abraham Lincoln Capital Airport (SPI) in Springfield offers commercial flights, and Springfield is served by Amtrak’s Lincoln Service and Texas Eagle trains at the downtown Amtrak station.

Frequently Asked Questions

Where is Sangamon County, Illinois?
It is in central Illinois, centred on Springfield, the state capital, about 100 miles northeast of St. Louis, Missouri.

What is the population of Sangamon County?
196,343 people, per the 2020 census.

How big is Sangamon County?
868 square miles (2,250 km2) of land plus 8.7 square miles (23 km2) of water.

What is the county seat of Sangamon County?
Springfield is the county seat and also the capital of Illinois.

How many towns are in Sangamon County?
27 incorporated places — 4 cities and 23 villages — plus numerous unincorporated communities across 26 townships.

What ZIP codes are in Sangamon County?
Springfield uses several ZIP codes led by 62701; surrounding villages such as Chatham (62629), Auburn (62615) and Rochester (62563) each have their own.

Why is Springfield significant to Sangamon County’s history?
It became the Illinois state capital in 1839 and was Abraham Lincoln’s home from 1837 until he left for the presidency in 1861.

More counties in this state: Towns and villages in Illinois.