Gail S. Horn was born in 1957 and grew up in New Ulm, Minnesota. After completing high school in 1976, she attended Hutchison Area Vocational Technical Institute for a year, and then worked as a clerk. She married a member of the Marine Corps in 1978, and was a military spouse. Her husband was assigned to Camp Lejeune in North Carolina, and then Kansas City. Horn signed up for delayed entry into the Marine Corps in 1983, attending boot camp from January through March of 1984.
Horn then attended various training courses in avionics, as well as NCO (Non-Commissioned Officer) School. Her first duty assignment was Marine Corps Air Station New River, in Jacksonville, North Carolina. Then, in 1987, she was assigned to Marine Corps Air Base Cherry Point, in Havelock, North Carolina. In 1991, she went to drill instructor duty, completing training and eventually becoming a senior drill instructor. Upon completing that tour of duty in 1995, at which time she was in the process of divorcing, Horn was assigned to Marine Corps Air Station Beaufort, North Carolina. From there, her unit deployed to Iwakuni, Japan in 1996 for nine months. Upon her return, Horn requested to return to Japan, and was sent to Okinawa for three years, this time bringing her four year old daughter.
Horn was then assigned to Headquarters Marine Corps as an enlisted career counselor, at Quantico, Virginia, and was there when 9/11 occurred. She was then assigned again to Marine Corps Air Station New River. From there, she did a seven month deployment to Iraq, from June of 2004 to January of 2005, based at Camp Al-Taqaddum, also known as “TQ”. She retired in 2008 as a sergeant major and master gunnery sergeant.