William Hamilton and Company built the ship in Port Glasgow on the River Clyde, launching her on 21 September 1911[1] and completing her that October.

[2] When the First World War started in 1914, all of the Isthmian Steamship Co's ships were transferred to the direct ownership of its parent company in the then-neutral USA, and re-registered there.

[6] She made four trips for the Naval Overseas Transportation Service: two to France before the Armistice of 11 November 1918 and two afterward to Uruguay, one of which included a visit to the United States Virgin Islands.

After being commissioned, Santa Rosalia went from New Orleans to Hampton Roads, Virginia, where she loaded United States Army general supplies.

She left in convoy on 19 June 1918, reached Brest, France on 9 July, and continued to Gironde[clarification needed] to discharge her cargo.

After transferring from a US Army to a US Shipping Board account,[clarification needed] she went to New York to load a cargo of general supplies.

She ran into a heavy sea, and on the evening of 17 February her wireless telegraph operator sent a distress signal stating that she was about 180 nautical miles (330 km) east of the Nantucket Light ship, leaking, and needing assistance.

The Greek steamship was about 500 nautical miles (930 km) east of Cape Henry when City of Newport News caught up with her on 18 February.

Stefanos Costomenis was abandoned at position 37°43′N 66°03′W / 37.717°N 66.050°W / 37.717; -66.050 and all 33 of her crew were safely transferred to City of Newport News, which then set course for Norfolk, Virginia.