Johnson's official Medal of Honor citation reads: He practically single-handed protected the left flank of his company's position in the offensive to break the German's gothic line.

Repeated enemy counterattacks, supported by artillery, mortar, and machinegun fire from the high ground to his front, had by the afternoon of 16 September killed or wounded all his men.

Collecting weapons and ammunition from his fallen comrades, in the face of hostile fire, he held his exposed position and inflicted heavy casualties upon the enemy, who several times came close enough to throw hand grenades.

On the night of 16–17 September, the enemy launched his heaviest attack on Company B, putting his greatest pressure against the lone defender of the left flank.

Johnson rushed to the shell hole where they lay half buried and seriously wounded, covered their position by his fire, and assisted a Medical Corpsman by the name of James L. Christopher from Mount Vernon, Ohio in rendering aid.