Melvin was born on the 27th of September 1948, in Wellsville, Ohio, where he grew up and attended school. He graduated from Wellsville High School in June of 1966, and the following month he enlisted into the US Marine Corps in Cleveland. After recruit training at Parris Island, Melvin was assigned to Camp Lejeune and completed infantry training, followed by special weapons training. He was a Private First Class when he deployed with the 5th Marines, 1st Marine Division to the Republic of Vietnam and it was his actions about two months before his 19th birthday that would cost him his life and earn him the Medal of Honor. The citation reads:

For conspicuous gallantry and intrepidity at the risk of his life above and beyond the call of duty while serving as a machine gunner attached to the 1st Platoon, Company F, 2d Battalion, on 3 and 4 July 1967. Pfc. Newlin, with four other marines, was manning a key position on the perimeter of the Nong Son outpost when the enemy launched a savage and well-coordinated mortar and infantry assault, seriously wounding him and killing his four comrades. Propping himself against his machine gun, he poured a deadly accurate stream of fire into the charging ranks of the Viet Cong. Though repeatedly hit by small-arms fire, he twice repelled enemy attempts to overrun his position. During the third attempt, a grenade explosion wounded him again and knocked him to the ground, unconscious. The Viet Cong guerrillas, believing him dead, bypassed him and continued their assault on the main force. Meanwhile, Pfc. Newlin regained consciousness, crawled back to his weapon, and brought it to bear on the rear of the enemy causing havoc and confusion among them. Spotting the enemy attempting to bring a captured 106 recoilless weapon to bear on other marine positions, he shifted his fire, inflicting heavy casualties on the enemy and preventing them from firing the captured weapon. He then shifted his fire back to the primary enemy force, causing the enemy to stop their assault on the marine bunkers and to once again attack his machine-gun position. Valiantly fighting off two more enemy assaults, he firmly held his ground until mortally wounded. Pfc. Newlin had singlehandedly broken up and disorganized the entire enemy assault force, causing them to lose momentum and delaying them long enough for his fellow marines to organize a defense and beat off their secondary attack. His indomitable courage, fortitude, and unwavering devotion to duty in the face of almost certain death reflected great credit upon himself and the Marine Corps and upheld the highest traditions of the U.S. Naval Service.

Melvin’s family received his Medal of Honor from President Nixon on the 18th of March 1969, in a ceremony at the White House. Melvin Earl Newlin is buried with his family in the Spring Hill Cemetery in Wellsville, Ohio: Section 18, Lot 47. His name appears on the National Vietnam Veterans Memorial in Washington DC: Panel 23E, Line 5.