18th Illinois Infantry Regiment
| 18th Regiment Illinois Volunteer Infantry | |
|---|---|
Illinois state flag | |
| Active | May 28, 1861, to December 31, 1865 |
| Country | United States |
| Allegiance | Union |
| Branch | Infantry |
| Engagements | Fort Henry Fort Donelson Battle of Shiloh Siege of Vicksburg |
The 18th Regiment Illinois Volunteer Infantry was an infantry regiment that served in the Union Army during the American Civil War.