618 Area Code: Belleville, Illinois

Southern Illinois is served by the 618 area code, with Belleville as the primary city in the directory's records. Belleville sits on the rolling country east of St. Louis in St. Clair County, on a stretch of land that historically anchored a substantial German immigrant community and the surrounding mining and agricultural economy. The 618 footprint extends from the metro-east cities along the Mississippi south to Carbondale (with Southern Illinois University's main campus), east into the Wabash River country, and down to the Ohio River along the southern tip of the state — a geographically large region with a relatively dispersed population.

Records linked to 618 numbers in the directory often include Aurora, Chicago, Cicero, and Peoria — Illinois cities outside the 618 footprint. The pattern reflects standard public-record dynamics, with phone numbers porting across Illinois and addresses linked across multiple cities. The directory currently documents 538 distinct prefixes within 618 in detail, a working subset of the prefix population the code carries.

Belleville's home values come in well below the US median, in line with broader downstate Illinois pricing. Median household income runs below the national figure, the city's median age sits a touch under the US reading, and population places Belleville as one of the larger metro-east cities — substantial within its St. Louis-area footprint but small in the broader Illinois context. The 618 footprint as a whole reflects a mix of metro-east suburbs, university towns, and rural counties spread across southern Illinois.