 For example, the 9th Massachusetts Volunteer Infantry Regiment (attached to the 5th Corp.) formed largely of Irish immigrants from the Boston area suffered the loss of 15 officers and 194 enlisted men in combat (as well as 3 officers and 66 enlisted men to disease) throughout the war and were central to many of its bloodiest battles.Initially led by charismatic Colonel Thomas Cass (himself an Irishman, born in Queens County), who died in 1862 after receiving wounds at the Battle of Malvern Hill, notable engagements included Mechanicsville, Gaines's Mill, Malvern Hill, Second Bull Run and Antietam.As well as notable involvements in a successful (yet possibly initially overlooked) holding action at Big Round Top during the Battle of Gettysburg, the regiment was also held supporting roles in the disasters of Fredericksburg and Chancellorsville.