4th Pennsylvania Infantry Regiment

4th Regiment, Pennsylvania Volunteer Infantry
National color of the 4th Pennsylvania Infantry Regiment, later carried by the 51st Pennsylvania Infantry Regiment
Active	April 20 – July 27, 1861
Country	United States
Allegiance	Union
Branch	Union Army
Type	Infantry
Size	39 officers and 756 men (at muster-in)[1]
Engagements	Bull Run campaign
Commanders
Notable commanders	John F. Hartranft

The 4th Pennsylvania Infantry Regiment, officially known as the 4th Regiment, Pennsylvania Volunteer Infantry, was an infantry regiment of the Union Army in the American Civil War. Formed mostly from a militia unit in Norristown in southeastern Pennsylvania, the regiment enlisted at the beginning of the American Civil War in April 1861 for a three-month period of service under the command of Colonel John F. Hartranft. Logistical difficulties bedeviled the regiment, which served as part of the garrison of Washington, D.C., until late June, when it was sent into Northern Virginia to join in the army of Brigadier General Irvin McDowell.

The regiment suffered its only combat casualties in a picket action on June 30 and was sent back to be mustered out on the eve of the First Battle of Bull Run owing to disagreement among the men over remaining with the army after the expiration of their term of service. Its men were denounced as cowards for being members of the only regiment to refuse to fight at the July 21 battle. Hartranft and a company commander remained with the army and later received the Medal of Honor for their actions at Bull Run. Many men of the regiment went on to serve in new Pennsylvania regiments, forming the bulk of the 51st Pennsylvania Infantry, which fought for the rest of the war.