4th Pennsylvania Reserve Regiment
| 4th Pennsylvania Reserve Regiment | |
|---|---|
Pennsylvania flag, c. 1863 | |
| Active | July 17, 1861 – June 8, 1864 |
| Country | United States |
| Allegiance | Union |
| Branch | Infantry |
| Engagements | |
| Pennsylvania U.S. Volunteer Infantry Regiments 1861–1865 | ||||
|
The 4th Pennsylvania Reserve Regiment, also known as the 33rd Pennsylvania Volunteer Infantry Regiment, was an infantry regiment that served in the Union Army during the American Civil War. It was a part of the famed Pennsylvania Reserves in the Army of the Potomac for much of the early part of the war and served in the Eastern Theater in several important battles, including Antietam and Fredericksburg.