He was promoted to private first class in September 1957, and was transferred to the 7th Infantry Company, USMCR, Louisville, Kentucky, to serve as a rifleman until March 1958.

Upon his return to the United States, he served as Guard/Company Police Sergeant, H&S Battalion, FMF, Atlantic, at Norfolk, Virginia, until March 1962.

[1][2] Upon his return to the United States in May 1967, he reported to the Marine Corps Recruit Depot, Parris Island, South Carolina.

[1] In the 1980s McGinty felt that there was a conflict between wearing his Medal of Honor (which bears the image of the Roman goddess Minerva) and his new-found Christian faith.

Second Lieutenant (then Staff Sergeant) John McGinty's platoon, which was providing rear security to protect the withdrawal of the battalion from a position which had been under attack for three days, came under heavy small arms, automatic weapons and mortar fire from an estimated enemy regiment.

With each successive human wave which assaulted his thirty-two-man platoon during the four- hour battle, Second Lieutenant John McGinty rallied his men to beat off the enemy.

With complete disregard for his safety, Second Lieutenant John McGinty charged through intense automatic weapons and mortar fire to their position.

Although he was painfully wounded as he moved to care for the disabled men, he continued to shout encouragement to his troops and to direct their fire so effectively that the attacking hordes were beaten off.

Second Lieutenant John McGinty's personal heroism, indomitable leadership, selfless devotion to duty, and bold fighting spirit inspired his men to resist the repeated attacks by a fanatical enemy, reflected great credit upon himself, and upheld the highest traditions of the Marine Corps and the United States Naval Service.On May 19, 2004, the South Carolina General Assembly passed Bill 5281, a resolution "commend[ing] the extraordinary heroism of Marine Staff Sergeant John J. McGinty III, a native of Massachusetts who entered the service in South Carolina, and who was awarded the Medal of Honor during the Vietnam Conflict for Valor.