Dahlgren is located in Hamilton County. About 504 people live here (as of 2020). Between 2010 and 2020, the population declined from 525 to 504. The region is at 156 meters above sea level. There are about 40 streets in Dahlgren. The region was founded in 1872. The postal codes are 62828. The dialing code is 618. The name originates from John Adolphus Dahlgren (United States Navy admiral) Dahlgren is human settlement in Illinois, United States of America.
| Named after | John Adolphus Dahlgren |
| Year built | 1872 |
| Area | 1 |
| Elevation | 156 m |
| Located in | Dahlgren Township |
| Postal code | 62828 |
| Country | United States |
| Population | 504 |
| Official name | Dahlgren |
| Bike path |
| Bike lane on roadway |
| Cycling allowed on bus lane |
| Bicycle street |
| Open to cyclists |
| Open to cyclists, good path |
| Cycling prohibited |
| Cobblestone |
| Long-distance bike route | (depending on scale) |
| Long-distance bike route |
| Long-distance hiking trail | (depending on scale) |
| Long-distance hiking trail |
| Pedestrians prohibited |
Public transit map Dahlgren Legend 
Bicycle map Dahlgren Legend 
Pedestrian map Dahlgren Legend