After unloading her cargo and undergoing availability for repairs, Union left Honolulu on 16 July en route to Eniwetok and Guam.

On 24 October 1945, Union anchored at Manila, then made a round trip to Subic Bay with Leo (AKA-60) to pick up landing craft replacements for the entire squadron.

The ship departed Manila Bay on 30 October for Haiphong, French Indochina, to embark elements of the 52nd Chinese Nationalist Army for transportation to Qinhuangdao, North China.

The ship returned to San Diego on 25 February and conducted a month of local operations before undergoing overhaul at the Puget Sound Naval Shipyard, Bremerton, Washington, from 31 March to 10 May 1949.

On 11 September, Union got underway for Jinsen, Korea, where boat landings took place four days later amidst mortar, machine gun, and rifle fire.

The next assignment for Union was the first of two resupply trips to the Pribilof Islands of St. Paul and St. George in the Bering Sea, the homeland of the largest fur-seal herd in the world.

She received orders to Korea and transported North Korean prisoners of war from Koje-do to Inchon in two trips which fully occupied the month of August.

After a restricted availability at Subic and a visit to Hong Kong, Union departed in February for the Tachen Islands where she and other ships assisted in the evacuation of Chinese Nationalist troops and refugee civilians.

After loading men and equipment of the 1st Marine Division at Inchon, Union departed on 3 April for a quick turn-around trip to San Diego.

She returned to Pusan, Korea, on 20 May and arrived back at San Pedro, California, on 12 June with Marine air group personnel and equipment.

Late in August, Union made a brief trip to Vancouver, British Columbia, to represent the United States Navy in the Pacific National Exhibit.

Union then visited Kure, Nagoya, and Chigasaki Beach before returning to Yokosuka to pick up Marine Corps cargo for Naha, Okinawa.

On 5 February, Union departed Yokosuka for Okinawa to prepare for Operation "Strongback," a major 7th Fleet amphibious assault exercise at Dingalen Bay, Luzon, Philippines, in which destroyers, cruisers, and carriers took part in screening, gunfire, and air support tasks.

On 10 July 1959, Union and Comstock (LSD-19) embarked the 3rd Anti-Tank Battalion and sailed for Numazu, Japan, to commence the first phase of Operation "Tankex."

During the first part of the deployment, the ship made stops at Guam; Okinawa; Subic Bay, Philippines; Hong Kong; and Yokosuka, Japan, conducting various cargo-personnel lifts.

May, June, and July were spent in the San Diego area, where Union underwent two intensive training periods followed by leave and upkeep.

The following year, the Department of Commerce would carry on this work with its own vessel, thus ending a Navy mission initiated in the 1920s by executive order of President Coolidge.

Upon her arrival at Pearl Harbor, the ship took part in Operation "Silver Sword," a landing exercise of 5,000 marines on the beaches of Maui.

After voyage repairs at Sasebo, Union steamed to Hong Kong where she served as station ship for the remainder of the year, 16 December 1961 through 14 January 1962.

Having brought good will to Shimoda, Union next steamed to Sasebo for upkeep, then on to Pusan, Korea, where she provided facilities for Korean units to stage a ship-to-shore movement.

Typhoon "Shirley" greatly hampered the landing phase of the operation, but it was finally completed despite torrential rains, floods, washed out roads, and dense fog.

After a port visit to Kure, Japan, Union off-loaded "Flagpole" gear at Buckner Bay, then underwent a period of upkeep at Yokosuka.

After a period of upkeep at Yokosuka, she visited Kobe, Japan, and met with an anti-American demonstration staged by the Japanese Peace Committee, a communist organization.

The crew received an unexpected treat when comedian Bob Hope and his troupe presented their annual Christmas show at Subic Bay on 28 December 1964.

She anchored briefly at Buckner Bay, Okinawa, before conducting four days of special operations culminating in a landing at Baie De Dung, Vietnam.

On 16 May, Union again returned to Buckner Bay, only to sail again four days later for Chu Lai harbor, Vietnam, conducting special operations en route.

The ship set course for Yokosuka, Japan, on 31 August; and, after a nine-day visit, Union sailed for Pearl Harbor, Hawaii, arriving there on 21 September.

Union then proceeded to Cam Ranh Bay, South Vietnam, where, on 15 September, elements of the Republic of Korea Marines were loaded for transportation to Chu Lai.

On 29 May 1967, Union suddenly received orders to perform duties as a reconnaissance ship, trailing the Russian trawler Peleng, which had been operating off the coast of southern California near Catalina and San Clemente Islands.

From 1 January to 1 August 1969, her schedule was filled with all types of operational training, inspections, and upkeep evolutions in the San Diego-San Francisco area.