Capella was built in 1920 as Comerant by American International Shipbuilding Corporation, Hog Island, Pennsylvania, under a Shipping Board contract; acquired by the Navy 20 November 1921; and commissioned 8 December 1921.

She was recommissioned 10 November 1938, and resumed supply runs along the east and west coast in alternate periods, on occasion penetrating Alaskan waters.

During July and August 1940 Capella assisted in the tow of the Navy's 10,700 ton New Orleans floating drydock from Balboa, Panama Canal Zone to Pearl Harbor, Hawaii.

[2] As war threatened and the United States began the buildup of Western Hemisphere bases acquired from the British, Capella was recalled to the east coast late in September 1940.

In June she cleared on the first of four transatlantic convoy crossings to Scotland, and North and West Africa, all so safely guarded as to be made without incident.