Robert S. Mueller 1969

[Sam McGee]

60. I had the same question

The guy pictured in the photo identified as Mueller is wearing a single stripe on his sleeve, indicating he is an Army private. There may be a rocker under the stripe indicating a Private First Class. Mueller was a USMC platoon leader . . . a 2nd Lieutenant.

From Wikipedia:

Mueller was accepted for officer training in the United States Marine Corps in 1968, attending training at Parris Island, Officer Candidate School, Army Ranger School, and Army jump school.[18]

In July 1968, he was sent to South Vietnam where he served as a rifle platoon commander with Second Platoon, H Company, 2nd Battalion, 4th Marines, 3rd Marine Division;[8][19] he eventually became aide-de-camp to 3rd Marine Division's commanding general.[18] In April 1969, he received an enemy gunshot wound in the thigh, recovered, and returned to lead his platoon until June 1969.[20] For his service in and during the Vietnam War, his military decorations and awards include: the Bronze Star Medal with Combat "V", Purple Heart Medal, two Navy and Marine Corps Commendation Medals with Combat "V", Combat Action Ribbon, National Defense Service Medal, Vietnam Service Medal with three  3⁄16" bronze stars, Republic of Vietnam Gallantry Cross, Republic of Vietnam Campaign Medal, and Parachutist Badge.[8][20]