On 7 December 1941, "Louisville", escorting and , was "en route" from Tarakan, East Borneo, to Pearl Harbor. She continued on to Hawaii, stopped briefly to survey the damage and proceeded on to California. There she joined Task Force 17 (TF 17) and steamed from San Diego on 6 January 1942, for Samoa, landing troops there on 22 January. Her first offensive operation of the war came on her return trip when she took part in carrier plane raids on 1–2 February on the Gilbert and Marshall Islands. During this action, one of her scout planes went missing and the pilot and aircrewman were lost.