Originally built in 1919 as SS Edgewood by Skinner and Eddy of Seattle, Washington, then transferred from the Shipping Board on 4 November 1921 and converted for naval use at Philadelphia Navy Yard.

Except for the period 1931 to 1934 when she served as barracks ship at Norfolk for the crews of battleships undergoing modernization, Denebola remained out of commission, at Philadelphia until she was towed to Baltimore, Maryland in 1940.

Again in full commission, on 6 April 1940 Denebola sailed to Norfolk for shakedown exercises in Chesapeake Bay, then returned to Baltimore to have flag quarters installed.

On 1 September she sailed for Halifax, Nova Scotia, arriving five days later, to prepare and transfer to the British government destroyers involved in the land bases-destroyers exchange.

During early 1941 Denebola served at Norfolk, tending destroyers and conducting schools in repair work, cruising to Guantanamo Bay, Cuba, once and to Bermuda twice.