Answer: The Irish Brigade
William McCarter was born in Derry, Ireland, in the 1840s, but was living in Philadelphia at the time of the Civil War. Recruiting for the 116th Pennsylvania, Infantry Regiment began in the summer of 1862 at the regiment’s headquarters at Seventh and Market Streets under Colonel Dennis Heenan; McCarter himself joined in August. The 116th was composed primarily of Irish American soldiers from Philadelphia, and the Irish Brigade was formed from the following regiments, as McCarter noted in his diary: the 69th New York, the 28th Massachusetts, the 88th New York, the 4th New York Artillery (acting as infantry), the 63rd New York, and the 116th Pennsylvania. “Every man in the Brigade wore a sprig of green box-wood in his cap,” McCarter noted in volume one of his manuscript.
With the 116th, McCarter fought in 26 battles, mostly in Virginia, including Fredericksburg (December 1862), Chancellorsville (May 1863), and Spotsylvania (May 1864).
HSP has William McCarter’s 1875 manuscript, “My Life in the Army,” in seven volumes (Am .6952), as well as a version published in 1996 (call number E 540.I6 M34 1996). A copy of St. Clair A. Mulholland’s The story of the 116th regiment Pennsylvania volunteers in the war of the rebellion; record of a gallant command is also available in HSP’s library (call number REF E 527.5 116th .M85 1903).