On 23 June 1945 Leary completed her shakedown off the US Naval base at Guantanamo Bay, Cuba and proceeded to her home port of Norfolk, Virginia.

In 1945 the Navy began converting 24 out of the 98 Gearings to radar picket ships (designated DDR in 1949) that could provide early warning of massed attack without overwhelming their Combat Information Centers.

She departed early January 1947 and later transited the Panama Canal to return to Norfolk and then Newport, Rhode Island before beginning East Coast operations.

Departing Newport on 29 October, Leary joined the U.S. 6th Fleet and made visits to ports in Algeria, Greece, Italy, and the island of Rhodes.

On 22 October 1962, the crew of Leary listened to President John F. Kennedy declare a quarantine of the island of Cuba in what became known as the Cuban Missile Crisis.

After the missiles were inspected and photographed, the Soviet ship was permitted to turn around and steam away due east from Cuba, with Leary trailing close behind.

[5] Between 24 April 1965, and 3 September 1965, she served on a peacekeeping mission off Santo Domingo as American troops were landed to prevent political chaos and subversion.

During periods of sustained air operations against North Vietnam Leary, along with the other destroyers on patrol, were responsible for providing protective cover for as many as three aircraft carriers at once.

Leary was also regularly called upon to provide emergency search and rescue duties, and was responsible for saving the lives of many who would otherwise have been lost at sea.

Leary was rotated out of combat in late 1965, and at the conclusion of her tour of duty, returned to her home port in Norfolk for routine maintenance.

On 5 July Leary once again passed through the Panama Canal and was quickly en route to an extended tour of duty off the coast of Vietnam.

[8] On arrival, she was immediately assigned to provide needed gunfire support off the Vietnamese coast as she alternated duty with the carriers on Yankee Station.

Periodically, Leary reinforced the 7th Fleet cruisers and she provided naval gunfire support to allied forces in South Vietnam.

Although it was reported that life aboard Sea Dragon destroyers proved stressful and tiring, morale consistently remained high because of the operation's effectiveness.

Then in January 1969 Leary again passed through the Panama Canal and was deployed for duty with the 7th Fleet providing gunfire support to U.S. operations in Vietnam until October 1969, after which she returned to her home port in Norfolk.

From January through October 1969 Leary made a Western Pacific cruise for extended deployment with the 7th Fleet providing gun fire support to US operations in Vietnam.

Leary was immediately dispatched to the scene, along with two United States Coast Guard cutters, two C-130 aircraft, the destroyer Hugh Purvis, and the cruiser Fox.

Leary returned one last time to Norfolk, and on 31 October 1973, stood-to for her decommissioning ceremony as she was recognized for her 28 years of distinguished and honorable service to the United States Navy.

Leary was carefully examined for weapons effects testing, and provided vital information on structural integrity and survivability which assisted in the design and planning of later destroyers.

Langara spent the next fourteen years serving with NATO and insuring the survival of the new Spanish democracy until the effects of age overcame the ship.