Union leaders were initially reluctant to establish ethnically based units but were soon swayed by the attractions of enhanced Irish recruitment to a brigade with its own Irish commanders. Significantly, Irish involvement meant the acceptance—for the first time in American life—of a large Catholic force. The brigade’s chief chaplain, Fr William Corby (later president of Notre Dame University, Indiana), became famous for administering absolution at Gettysburg.The secretary of war, Simon Cameron, authorised the brigade’s formation in September 1861; it consisted initially of three New York infantry regiments—the 63rd, 69th and 88th. Its commanders and rank-and-file had known Fenian connections. It was quickly joined by the mainly Scots-Irish 29th Massachussets regiment. The alliance withstood ancient animosities and earned plaudits for hard campaigning during the Seven Days Battles (June 1862), notably at Savage’s Station, Glendale and Malvern Hill. Later, the New Englanders were replaced by a wholly Irish regiment from Philadelphia, the 116th.The brigade distinguished itself throughout the conflict but with increasing casualties. By June 1864 it was reduced to almost regimental size. When its last prestigious commander, Col. Richard Byrne, fell, its remnants were incorporated into the 3rd and 4th Brigades, 1st Division Corps. Officially designated the ‘Fighting 69th’, it continued to serve. Sections of the brigade still participate in New York’s St Patrick’s Day parade.