US MARINE CORPS
William Dean O'Brien
July 3, 1929—June 22, 2020
1STLT
Life Timeline
90 years1929
Born
July 3, 1929
US MARINE CORPS
Service Record
Korean War
Korean War
Conflict
1STLT
2020
Passed Away
June 22, 2020
Service Record
Verified fields from cemetery source data.
Branch
US MARINE CORPS
Rank
1STLT
War / Conflict
Korean War
Sourced from official cemetery data; last updated May 30, 2026.Learn more