 Complete the following phrase:  Upon the outbreak of the American Civil War, Jones readily joined the Union Army. On July 7, 1861, he enlisted with the 37th New York Volunteers, popularly known as the Irish Rifles, under Colonel John H. McCunn. He was initially a private but quickly found himself elected to the rank of second lieutet by the men in the regiment. He was present at the First Battle of Bull Run, only two weeks after his enlistment, but saw no action as the unit was held in reserve. Jones displayed gallant conduct during his first years with the regiment and soon rose in rank to first lieutet and adjutant on November 4, 1861, and then major on January 21, 1862. He and the Irish Rifles later joined General Samuel P. Heintzelmans III Corps, as part of the 3rd Brigade of the 3rd Division under Brigadier General Philip Kearny, during the Peninsula campaign and participated in 