On 18 August 1937 the Cassin was in dry dock #2 at the Philadelphia Navy Yard when she suffered a ruptured steam line.

[5] Recommissioned 5 February 1944, Cassin reported at Pearl Harbor 22 April, and was assigned escort duty from Majuro until August.

By shooting out caves and bombarding Aguijan, she aided in the consolidation of Tinian from 15 – 25 August, and then assumed escort duties out of Saipan.

However, when TF 38 made contact with the Japanese Center Force rounding the southern cape of Mindoro, bound for its part in the Battle for Leyte Gulf, Cassin's group was recalled to join the approaching action.

In the afternoon of 25 October, her group at last reached position to launch aircraft which attacked the Japanese ships in one of the longest-range carrier strikes of the war.

On the night of 11–12 November 1944, and again on 24 January 1945, she bombarded the island, and otherwise engaged in patrol, escort, and radar picket duties around Saipan.

On 20 July, she bombarded Kita-Iwō-jima, and on 7 August, she boarded and searched a Japanese hospital ship to ensure compliance with international law.

[6] The Ensign that was flying on the ship during the attack on Pearl Harbor is currently displayed in the Jerry Falwell Library on the campus of Liberty University.