LeBourgeois first assignment was as a gunnery officer aboard the light cruiser , then in combat against the Japanese in the Pacific. Aboard "Columbia" he saw action in the Palau campaign, including the Battle of Peleliu, and in the Leyte campaign, during which "Columbia" fought in the Battle of Surigao Strait, a part of the Battle of Leyte Gulf. "Columbia" also supported the invasion of Mindoro and took part in the invasion of Lingayen Gulf on Luzon, during which three "kamikaze"s struck "Columbia" and for which the ship was awarded a Presidential Unit Citation. After that, "Columbia" operated in support of the invasion of Balikpapan and took part in the 1945 antishipping sweep in the South China Sea.