 Complete the following phrase:  Nineteen-year-old Sylvester Bonnaffon Jr. enrolled for military service in Philadelphia, Pennsylvania on December 14, 1861, and mustered in there that same day as a private with Company I of the 99th Pennsylvania Volunteer Infantry. Transferring to Company G within the same regiment on December 18, he was then promoted to the rank of corporal on April 1, 1862 and to the rank of sergeant a month later on May 1. Commissioned as a second lieutet on August 1 of that same year, he subsequently engaged with his regiment in several of the most intense actions of the American Civil War as part of the Unions Army of the Potomac, including 1862s Second Battle of Bull Run August 2830 and battles of Chantilly September 1 and Fredericksburg December 1115; 1863s Chancellorsville Campaign April 30May 6, battles of Gettysburg July 13 and Wapping Heights July 23, Bristoe Campaign and its First Battle of Auburn October 13 and Second Battle of Rappahannock Station November 7, and the Mine Run Campaign November 27December 2; and 1864s battles of the Wilderness May 57, Spottsylvania Court House May 821, North Anna May 2326, and Cold Harbor May 31June 12. Engaged with his regiment in the Siege of Petersburg, including the 