For extraordinary heroism and intrepidity above and beyond the call of duty as a pilot in Marine Fighting Squadron 124 in aerial combat against enemy Japanese forces in the Solomon Islands area. Determined to thwart the enemy's attempt to bomb Allied ground forces and shipping at Vella Lavella on 15 August 1943, 1st Lt. Walsh repeatedly dived his plane into an enemy formation outnumbering his own division six to one and, although his plane was hit numerous times, shot down two Japanese dive bombers and one fighter. After developing engine trouble on 30 August during a vital escort mission, 1st Lt. Walsh landed his mechanically disabled plane at Munda, quickly replaced it with another, and proceeded to rejoin his flight over Kahili. Separated from his escort group when he encountered approximately 50 Japanese Zeros, he unhesitatingly attacked, striking with relentless fury in his lone battle against a powerful force. He destroyed four hostile fighters before cannon shellfire forced him to make a dead-stick landing off Vella Lavella where he was later picked up. His valiant leadership and his daring skill as a flier served as a source of confidence and inspiration to his fellow pilots and reflect the highest credit upon the U.S. Naval Service.