USS Clay was originally laid down as Sea Angel by the Western Pipe and Steel Company on 14 October 1942.

After an abortive operation against Kavieng (cancelled due to neutralization of the Japanese forces there by other means), USS Clay headed to Saipan, where on the morning of 15 June 1944 she participated in a feint landing off the island's northwestern coast in order to draw Japanese troops away from the real landing zone.

After more rehearsals, USS Clay embarked in March with elements of the 6th Marines as part of the massive invasion fleet destined for Okinawa.

By 5 April Clay was returning home to San Francisco for an overhaul and an increase in her armament in preparation for the invasion of Japan.

On 27 July USS Clay headed once more for the Pacific, but before she could arrive the US unleashed its atomic bombs on Nagasaki and Hiroshima and the Japanese surrendered.

Sailing through swept minefields and past the wreck of the Japanese battleship Nagato, USS Clay disembarked her cargo in the devastated industrial region between Yokohama and Tokyo, before returning to Cebu and thence to Otaru with more occupation troops.

From there she sailed to Saipan to embark troops returning home to the United States, arriving at San Pedro on 5 December 1945.