"Southampton" stood out of Portland on 11 January 1946 and arrived in San Francisco on the 13th. There she loaded cargo and mail before heading west on the 27th. The attack cargo ship stopped at Eniwetok from 9 to 15 February to discharge cargo and arrived at Guam on the 18th. For almost a month, she discharged and loaded cargo at Guam. On 16 March, she headed back to San Francisco. Ten days later, her destination was changed to Port Hueneme, California. "Southampton" was at Port Hueneme for the first ten days of April before putting to sea on her final voyage. On 10 April, she headed south to the Canal Zone; transited the canal on the 20th; and arrived in Baltimore on the 27th.