He took command of USS Quincy (CA-39) on 20 May 1942 and died on the night of 8–9 August 1942 when that cruiser was sunk while fighting in the Battle of Savo Island.

Following shakedown off Bermuda, the new destroyer steamed, via the Panama Canal and Pearl Harbor, to the Pacific war zone, arriving at Ulithi on 3 November 1944.

In an attack on the night of 22 and 23 July, she launched torpedoes at enemy shipping off the east entrance to Sagami Wan, Japan.

After Japan capitulated, Samuel N. Moore aided occupation forces, visiting Shanghai and Tsingtao, China, and Pusan, Korea.

Sailing again for the Far East on 1 December, she guarded carriers and bombarded enemy shore installations in Korea from February to May 1952 before returning to San Diego on 26 June.

In April, she aided the defense of Yang-do Island and patrolled near Chongjin; in May, she fought enemy shore batteries at Wonsan Harbor.

Sailing from the West Coast for the western Pacific on 28 September 1965, she provided gunfire support off Vietnam, operated as a plane guard in the South China Sea, and fired on targets in the Mekong Delta, before returning to Long Beach on 8 April.

Getting underway again for the western Pacific on 28 March 1967, she patrolled off North Vietnam, as part of Operation Sea Dragon, and protected aircraft carriers in the Tonkin Gulf, before arriving at Long Beach on 20 September.