The ship was laid down as HMS Espoir (BAM-23) for the Royal Navy on 27 October 1942 at Seattle, Washington, by the Associated Shipbuilding Corp.

She entered the lagoon at Majuro on 25 May; two days later, headed back to Hawaii with 24 passengers embarked; and reached Pearl Harbor on 2 June.

On 8 September, she departed Guadalcanal with Task Group (TG) 32.4, the transport screen for the Palau Islands invasion force.

Minesweeping operations continued on a daily basis until 18 September when Triumph was devoted entirely to screening and harbor control duties.

She remained there until late November, performing antisubmarine screening duty at Peleliu in the south and at Kossol Passage in the north, as well as escorting ships between the two.

Triumph reached recently invaded Leyte on the morning of 30 November and began preparations for the flanking landings at Ormoc Bay on the western shore of the island.

Unmolested, the group of minesweepers completed their sweeping by 2125 that night and took up station in the screen of the Ormoc Bay attack force.

Though the attacks cost the American naval forces two warships sunk, Mahan (DD-364) and Ward (APD-16), two more severely damaged, Liddle (APD-60) and Lamson (DD-367), and an LSM abandoned; they failed to impede the landings and the progress of the troops ashore.

The raids ceased at dark; and, early the next morning, task unit TU 78.3.6 reentered San Pedro Bay.

Just after midday, a kamikaze crashed into the flagship Nashville (CL-43), and the light cruiser was forced to drop out of formation and return to San Pedro Bay with Stanly (DD-478).

By the morning of 14 December, the unit was passing Negros Island; and Triumph, along with the rest of the minesweepers, received orders to sweep the waters ahead of the force.

At 1830, she departed Mindoro and, after a brief but intense aerial attack at dusk, voyaged peacefully back to the anchorage at San Pedro Bay, anchoring there a little after 0800 on the 18th.

Though the main task force was subjected to incessant enemy air attacks, the minesweeper continued her mine-sweeping almost unmolested.

On the 9th, the ground troops stormed ashore at Lingayen, and Triumph kept a close watch for enemy submarines and suicide boats.

She remained in Lingayen Gulf until the 14th — riding at anchor during the last three days of that period — and then got underway with a Leyte-bound convoy of LST's and LCI's.

Early in the afternoon of 19 March, Triumph sailed put of the lagoon at Ulithi with the Ryukyu Islands invasion force.

When she arrived at her destination early on the morning of the 24th, Triumph and her division mates joined the Shea (DM-30) and a patrol craft in minesweeping operations.

Two ships of Triumph's unit proceeded to assist the stricken warship but managed to rescue only 172 members of Halligan's 325-man complement.

She and her colleagues concluded their mission on the eve of the landings, 31 March, and began duty with the task force's antisubmarine screen.

At 0600 the following morning — April Fool's Day and Easter Sunday rolled into one — landing craft started their move shoreward; and, soon thereafter, the first wave of U.S. Marines and soldiers hit the beaches on Okinawa.

On several occasions during that time, she became directly involved in the incessant air attacks launched by the Japanese against the invasion force.

On 16 April, when Taluga (AO-62) received a kamikaze hit, Triumph was soon at hand to rescue three men blown overboard in the action.

At dusk, Triumph was patrolling north of Kerama Retto when an enemy torpedo bomber executed a near-perfect run on her.

She arrived in the assigned area with the rest of her unit on the 5th and conducted a highly productive, eight-day sweep unimpaired by Japanese air activity.

After serving in the antisubmarine screen of the ships forced out of the anchorage, the warship returned to Buckner Bay on 21 July and remained there, awaiting orders, until 5 August.

She underwent an extensive overhaul at the Kaiser shipyard at Richmond, California, from 19 January to 12 June 1946 and then began operations along the west coast.

Operating out of Charleston, South Carolina, the minesweeper served along the southern portion of the eastern seaboard and in the Caribbean until mid-September when she deployed to the Mediterranean for service with the U.S. 6th Fleet.

Following another tour of duty in the western Atlantic early in 1954 and a second deployment to the Mediterranean during the winter of 1954 and 1955, Triumph began preparations for deactivation in the spring of 1955.