Navy Secretary Ray Mabus presented Seath with the Marine Corps' second-highest medal for valor in a ceremony in Quantico, Va. Seath also received a Bronze Star with "V" for valor for his actions during fighting the night before the battle that earned him the Navy Cross.
The Defense Department said in a release Seath, then a lance corporal deployed as a machine gun team leader with the 3rd Marine Division's Company K, 3rd Battalion, 4th Marine Regiment, saved almost an entire company of fellow Marines in 1966.
He halted an assault by North Vietnamese soldiers on July 16, 1966, using an M-60 machine gun he reassembled from spare parts to lay down fire that repelled the attacker while exposing himself to enemy fire.
The night before, he dragged two wounded Marines to safety while under heavy machine-gun fire.
"What Ned went through -- what he did -- is emblematic of the Marine Corps," Mabus said. "This is one of the biggest honors I have. Ned Seath is a hero."
His heroics went unrecognized until a fellow Marine, Bill Hutton, began the effort to have him honored.
"If it weren't for Ned Seath, I'd be buried right now ... in Arlington [National Cemetery]," Hutton said. "We were surrounded and outnumbered. But Ned didn't quit. He went above and beyond the call of duty. He saved a company of Marines."