The 20th Pennsylvania Volunteer Infantry was a volunteer infantry

Infantry

Infantrymen are soldiers who are specifically trained for the role of fighting on foot to engage the enemy face to face and have historically borne the brunt of the casualties of combat in wars. As the oldest branch of combat arms, they are the backbone of armies...

 regiment

Regiment

A regiment is a major tactical military unit, composed of variable numbers of batteries, squadrons or battalions, commanded by a colonel or lieutenant colonel...

 in the Union Army

Union Army

The Union Army was the land force that fought for the Union during the American Civil War. It was also known as the Federal Army, the U.S. Army, the Northern Army and the National Army...

 during the American Civil War

American Civil War

The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...

.

History

Recruitment for the regiment began on Friday, April 26, 1861 and by Saturday evening, the ranks were full. William H. Gray was elected colonel

Colonel

Colonel , abbreviated Col or COL, is a military rank of a senior commissioned officer. It or a corresponding rank exists in most armies and in many air forces; the naval equivalent rank is generally "Captain". It is also used in some police forces and other paramilitary rank structures...

, George Moore as lieutenant colonel

Lieutenant colonel

Lieutenant colonel is a rank of commissioned officer in the armies and most marine forces and some air forces of the world, typically ranking above a major and below a colonel. The rank of lieutenant colonel is often shortened to simply "colonel" in conversation and in unofficial correspondence...

, and Andrew H. Tippin as major

Major

Major is a rank of commissioned officer, with corresponding ranks existing in almost every military in the world.When used unhyphenated, in conjunction with no other indicator of rank, the term refers to the rank just senior to that of an Army captain and just below the rank of lieutenant colonel. ...

. It was mustered into service the following week and spent some time in Philadelphia drilling. It was assigned to Major General Robert Patterson

Robert Patterson

Robert Patterson was a United States major general during the Mexican-American War and at the beginning of the American Civil War...

's Army of the Shenandoah

Army of the Shenandoah (Union)

The Army of the Shenandoah was a Union army during the American Civil War. First organized in 1861 and then disbanded, it is best known for its recreation in 1864 under Philip Sheridan...

 as part of the 3rd brigade, First Division. It took part in the advance which intended to pin down General Joseph E. Johnston

Joseph E. Johnston

Joseph Eggleston Johnston was a career U.S. Army officer, serving with distinction in the Mexican-American War and Seminole Wars, and was also one of the most senior general officers in the Confederate States Army during the American Civil War...

's Army of the Shenandoah

Army of the Shenandoah (Confederate)

The Army of the Shenandoah was an army of the Confederate States of America during the American Civil War. Major General Kenton Harper of the Virginia Militia organized about two thousand volunteers at Harpers Ferry by April 21, 1861. Brig. General Thomas J. "Stonewall" Jackson of the Virginia...

. On July 24, it was ordered back to Philadelphia, where it was mustered out August 6.

Casualties

• Killed and mortally wounded: ? officers, ? enlisted men
• Wounded: ? officers, ? enlisted men
• Captured or missing: ? officers, ? enlisted men
• Died of disease: ? officers, ? enlisted men
• Total: ? officers, ? enlisted men