Pre-World War I

First fixed-wing aircraft landing on a warship: Ely landing his plane on board Pennsylvania in San Francisco Bay on 18 January 1911

Pennsylvania operated on the east coast of the United States and in the Caribbean Sea until 8 September 1906, when she cleared Newport for the Asiatic Station, returning to San Francisco on 27 September 1907, for west coast duty. She visited Chile and Peru in 1910.^[4]

At 10:48, on 18 January 1911, Eugene Ely, flew a Curtiss Model D from Tanforan Racetrack in San Bruno, California, and at 11:01, landed on board Pennsylvania while she lay at anchor off Hunters Point, in San Francisco Bay. The plane made a smooth landing from astern onto a specially built 130-by-32-foot (39.6 by 9.8 m) platform. At 11:58, the plane took off and returned to Selfridge Field, completing the earliest demonstration of the adaptability of aircraft to shipboard operations.^[4]

In another of these early demonstrations, civilian aircraft designer and entrepreneur Glenn Curtiss taxied a hydroaeroplane alongside Pennsylvania as she lay anchored in San Diego Harbor, during the forenoon watch on 17 February 1911. The plane landed alongside the ship at 08:45 and sailors manned the cruiser's crane to hoist the machine on board. At 09:05, Pennsylvania hoisted the aircraft out and it returned to base.^[4]

While in reserve at Puget Sound, from 1 July 1911 – 30 May 1913, the cruiser trained naval militia. She was renamed Pittsburgh on 27 August 1912, to free the name Pennsylvania for a new battleship.^[4]

World War I

Recommissioning, Pittsburgh patrolled the west coast of Mexico, during the troubled times of insurrection that led to American involvement with the Veracruz landing in April 1914. Later she served as flagship for Admiral William B. Caperton—Commander in Chief, Pacific Fleet—during South American patrols and visits during World War I. Cooperating with the British, she scouted German raiders and acted as a powerful deterrent against their penetration of the eastern Pacific.^[4]

While at Rio de Janeiro, in October and November 1918, failure to implement quarantine procedures by Captain George Bradshaw, led to the spread of the deadly strain of Spanish influenza on ship, sickening 663 sailors (80% of the crew) and killing 58 of them.^[4]

Future Rear Admiral Ellis M. Zacharias served as a line officer aboard Pittsburgh during World War I. Future Governor of American Samoa George Landenberger commanded the vessel.^[5]

Inter-war period

Returning to the east coast, Pittsburgh prepared for duty as flagship for Commander, US Naval Forces in the eastern Mediterranean, for which she sailed from Portsmouth, New Hampshire on 19 June 1919. Cruising the Adriatic Sea, Aegean Sea, and Black Sea, she joined in the massive relief operations and other humanitarian concerns with which the Navy carried out its quasi-diplomatic functions in this troubled area. In June 1920, she sailed north to visit French and British ports and cruise the Baltic Sea on further relief assignments.^[4]

On 9 September 1920, she ran aground on rocks in the Baltic Sea off Libau. She was assisted by HMS Dauntless and Frederick; Frederick escorted her to Sheerness Royal Dockyard, Kent, England which she reached at 10:00 o'clock in the morning of 23 September. Before 12 October she had moved up river to Chatham Dockyard where she went into dry dock. On that date a team from Pittsburgh routed a team of British officers 21–8 at baseball. The following month, with Pittsburgh still in dry dock, a court-martial absolved Captain Todd of blame for the grounding but the navigator and watch officer were held accountable.^[6] She returned to decommission at Philadelphia, on 15 October 1921.^[4]

Recommissioned on 2 October 1922, Pittsburgh returned to European and Mediterranean waters as flagship of Naval Forces Europe,^[4] arriving in Gibraltar on 19 October. On 23 October, she hoisted the flag of Vice Admiral Long when Utah returned to the US. By 10 July 1923, Pittsburgh was in the harbor at Cherbourg, France, to disembark 3 officers and 60 enlisted men of her Marine Detachment. They were detailed to travel to the dedication of the Belleau Wood National Monument to the American Expeditionary Force. The Battle of Belleau Wood was where the US Marine Corps made a famous stand during the Allied Campaign of 1918. In 1923, when docked in Amsterdam, the crew of Pittsburgh took part in another baseball game, this time against a team of Dutch players. The details of the game are not known, but it is known that Pittsburgh team won. It would be the first of several games Dutch players would play with US Navy crews.^[7] Pittsburgh became flagship for two of the Commanders-in-Chief, US Naval Forces European Waters, Admiral Philip Andrews in 1924–1925 and Vice Admiral Roger Welles in 1925–1926.^[6]

The ship arrived at New York on 17 July 1926, to prepare for flagship duty with the Asiatic Fleet, during which time she was partially refitted, including the removal of her forward stack (making her unique to her class)^[6] and removal and plating over several 3-inch guns. She sailed on 16 October, for Yantai, arriving on 23 December. Early in January 1927, she landed sailors and Marines to protect Americans and other foreigners in Shanghai, from the turmoil and fighting of the Chinese power struggle. When Chiang Kai-shek's National Revolutionary Army won control of Shanghai, in March, Pittsburgh resumed patrol operations and exercises with the Asiatic Fleet. Closing her long career of service, she carried the Governor General of the Philippines, Dwight F. Davis, on a courtesy cruise to such ports as Saigon, Bangkok, Singapore, Belawan, Batavia (Jakarta), Surabaya, Bali, Makassar, and Sandakan, returning to Manila, on 15 April 1931. Six days later, she steamed for Suez, en route to Hampton Roads, arriving on 26 June. She was decommissioned on 10 July, and under the terms of the London Naval Treaty, sold for scrapping to Union Shipbuilding, Baltimore, Maryland on 21 December.^[4]