On that day, in the Ap Bac Zone, Republic of Vietnam, Keller and fellow soldier Specialist Four Raymond R. Wright stormed a series of enemy bunkers which were firing on their unit.

[2] The medal was formally presented to him on September 19, 1968, by President Lyndon B. Johnson during a ceremony at the White House.

[1] After being discharged from the military in August 1968, Keller married a United States Navy veteran and eventually moved to Milton, Florida.

[3] Sergeant Keller's official Medal of Honor citation reads: For conspicuous gallantry and intrepidity in action at the risk of his life above and beyond the call of duty.

Keller's unit suddenly came under intense automatic weapons and small-arms fire from a number of enemy bunkers and numerous snipers in nearby trees.

Keller neutralized the fire from the first bunker with his machine gun, the other soldier threw in a hand grenade killing its occupant.

Keller and his comrade had been almost continuously exposed to intense sniper fire as the enemy desperately sought to stop their attack.

Keller's selfless heroism and indomitable fighting spirit saved the lives of many of his comrades and inflicted serious damage on the enemy.