Walter Knapps was born in February 1921 in New Roads, Louisiana. His mother died in a house fire when he was six years old and his father died two years later in a sawmill accident, where he was working. Knapps was raised by his grandparents after the loss of his parents. When he turned 19, Knapps joined the United States Marine Corps. He completed his basic training at San Diego, California and was then sent to Pearl Harbor, Hawaii. He was stationed on Ford Island [Annotator's Note: Ford Island Naval Air Station, Pearl Harbor, Hawaii] where he was assigned to guard duty.

Walter Knapps was a Marine Corps security guard on Ford Island Naval Air Station at Pearl Harbor, Hawaii on the morning of 7 December [Annotator's Note: the Japanese attack on Pearl Harbor, Hawaii occurred on 7 December 1941]. Knapps was in the mess hall eating breakfast when the Japanese attacked. The planes were flying slowly as they attacked American ships with bombs and torpedoes. Knapps and those near him had no rifles or ammunition. It took a good while to arm themselves for the defense. Everyone was excited and running all over not knowing what was going on. The Japanese never fired a shot at Knapps. Hickam Air Force Base [Annotator's Note: Hickam Field in Honolulu, Hawaii] was hit hard. The enemy was after the ships and got them. After the attack, the troops got equipped in case the Japanese tried to invade the island. Aircraft arriving from the United States were shot down when the American forces mistook them for the enemy.

[Annotator's Note: he was], Walter Knapps [Annotator's Note: a Marine guard on Ford Island Naval Air Station during the Japanese attack on Pearl Harbor, Hawaii on 7 December 1941] was sent back to the United States after the attack to Camp Lejeune [Annotator's Note: Marine Corps Base Camp Lejeune in Jacksonville, North Carolina]. He drove a fire truck while there. He was assigned to the 1st Marine Division [Annotator's Note: Company I, 3rd Battalion, 1st Marine Regiment, 1st Marine Division] and was with them when they landed on Okinawa [Annotator's Note: Battle of Okinawa, codenamed Operation Iceberg, 1 April to 22 June 1945 at Okinawa, Japan]. He was wounded in the knee during the fighting. The Japanese were hidden in a ditch when he was hit. After being wounded, he had surgery as the fighting raged on. The Japanese fought well. They were tough. He was sent back to the United States for further treatment. He spent a year convalescing in the California hospital. He was happy, happy, happy when the war ended. He wanted to stay in the Marine Corps after the war, but his wound prevented him from doing so. Knapp was discharged in 1946 and returned to Ponchatoula [Annotator's Note: Ponchatoula, Louisiana]. His ability to walk has deteriorated over the years.