Career
The battle was the decisive engagement of Major General Philip Sheridan’s Valley Campaigns of 1864 and was the largest battle fought in the Shenandoah Valley. McGonnigle was commissioned as a Captain of Volunteers in March 1864, and served as an assistant quartermaster in the Army of the Shenandoah under General Philip Sheridan. He was transferred to the regular army Quartermaster Corps with the same rank in May 1865.
He received a promotion to Major in February 1882, and retired from the Army in March 1893.