"Charleston" sailed from Norfolk, Virginia on 24 February 1937 to join Squadron 40T, in which she visited Dubrovnik, Yugoslavia, Trieste, Naples, Italy, and Algiers before returning to the Charleston Navy Yard for updating on 24 April. On 9 July, she sailed to Balboa, Panama for extensive training and combat exercises in the Panama area before returning north back to Charleston on 1 March 1938.