99th Pennsylvania Infantry in the American Civil War

Overview

The 99th Pennsylvania Infantry (Union Army, Infantry) was organized in Philadelphia, Pennsylvania, with recruitment primarily from Philadelphia men, many of whom had previously served in the 22nd Pennsylvania. The regiment was mustered into United States service at various times from July 1861 to February 1862. Serving in the Eastern Theater, the 99th Pennsylvania Infantry participated in numerous major campaigns and engagements with the Army of the Potomac, distinguishing itself in several key battles.

The regiment was attached to various brigades and divisions throughout its service, including the 2nd Brigade, 1st Division, 3rd Corps, and later the 1st Brigade, 3rd Division, 2nd Corps. The 99th Pennsylvania Infantry was mustered out of service on July 1, 1865, after participating in the Grand Review in Washington, D.C.

Organization & Service

The 99th Pennsylvania Infantry was organized in Philadelphia, with companies mustered into service between July 1861 and February 1862. The first three companies departed for Washington, D.C., on August 8, 1861, encamping near Alexandria, Virginia. The remaining companies joined as they were organized. On February 19, 1862, the regiment was ordered to Washington for garrison duty at various forts, and in April 1862, it was assigned to similar duty along the Anacostia River, from Burning Bridge to Alexandria.

On July 4, 1862, at Harrison’s Landing, the regiment was assigned to the 2nd Brigade, 1st Division, 3rd Corps, Army of the Potomac. The 99th participated in the Peninsula Campaign and was engaged at the Second Battle of Bull Run. It was present at Chantilly but not actively engaged at Antietam. The regiment next saw significant action at Fredericksburg in December 1862.

In May 1863, the 99th Pennsylvania Infantry took part in the Battle of Chancellorsville, notably participating in the charge led by General Kearny. The regiment remained in the area until the Gettysburg Campaign, where it was heavily engaged on July 2, 1863, suffering substantial losses and receiving commendations from Generals Ward and Birney for its conduct.

Following Gettysburg, the regiment camped near Warrenton Sulphur Springs until October 1863. On November 7, it captured a large number of prisoners at Kelly’s Ford. The 99th participated in the Mine Run Campaign and wintered at Brandy Station. In February 1864, many members reenlisted and were furloughed, returning in April. Upon reorganization of the Army of the Potomac, the regiment became part of the 1st Brigade, 3rd Division, 2nd Corps.

During the Overland Campaign, the 99th was engaged at the Wilderness, holding its ground under heavy fire and receiving thanks from General Birney. At Spotsylvania, the regiment took part in the charge of the 2nd Corps, capturing battle flags, artillery, and prisoners. The regiment continued to see action at Petersburg, Deep Bottom, and in operations around Poplar Grove Church and the Boydton Plank Road. It participated in the raid on the Weldon Railroad and spent the winter of 1864–65 at Fort Seibert near the Vaughan Road.

In early 1865, the 99th Pennsylvania Infantry fought at Hatcher’s Run and near the Davis House. It was active at Sailor’s Creek and Appomattox Court House, where it witnessed the surrender of the Army of Northern Virginia. The regiment then moved to Richmond and Washington, D.C., participated in the Grand Review, and was mustered out on July 1, 1865.

Engagements & Campaigns

• Peninsula Campaign
• Second Battle of Bull Run
• Chantilly
• Fredericksburg
• Chancellorsville
• Gettysburg
• Kelly’s Ford
• Mine Run Campaign
• The Wilderness
• Spotsylvania
• Petersburg
• Deep Bottom
• Poplar Grove Church
• Boydton Plank Road
• Weldon Railroad Raid
• Hatcher’s Run
• Sailor’s Creek
• Appomattox Court House

Casualties

Specific casualty figures for the 99th Pennsylvania Infantry are not provided in the available primary sources. Fox’s Regimental Losses and state reports may contain more detailed statistics.

Field Officers & Commanders

• Colonel Thomas W. Sweeny
• Colonel Peter Fritz, Jr.
• Colonel Asher S. Leidy
• Colonel Edward R. Biles
• Lieutenant Colonel William P. Seymour
• Lieutenant Colonel Asher S. Leidy
• Lieutenant Colonel Edward R. Biles
• Lieutenant Colonel John W. Moore
• Lieutenant Colonel Peter Fritz, Jr.
• Major Asher S. Leidy
• Major Henry A. Read
• Major John W. Moore
• Major Peter Fritz, Jr.
• Major G. W. Tomlinson

Regimental Roster

The complete roster of officers and enlisted men who served in the 99th Pennsylvania Infantry is available for genealogical and historical research. This roster includes names, ranks, and service details as recorded in official state and federal records.

To view the full roster, visit the 99th Pennsylvania Infantry Regimental Roster page.

Sources & References

• Official Records of the Union and Confederate Armies, Series I, various volumes and parts
• Pennsylvania State Adjutant General’s Reports
• Dyer, Frederick H., A Compendium of the War of the Rebellion
• Fox, William F., Regimental Losses in the American Civil War
• The Union Army, Federal Publishing Company, 1908, Volume 1