"Mississinewa", second of a class designed to provide fuel, food, stores, and mail services rapidly and for sustained periods to ships at sea, operated primarily along the U.S. East Coast, with one brief Mediterranean deployment, until 1 May 1956. She then departed her original home port, Newport, Rhode Island, for Naples, Italy. With Naples as her home port, the tanker cruised the Mediterranean servicing the 6th Fleet in normal and crisis operations until 1964. During the fall of 1956 and early winter 1957, she supported 6th Fleet ships as they stood by in case they were called on to intervene in the Suez Crisis and the tense period that followed. Again, in mid‑July 1958, she got underway on short notice to provide logistic support to ships of the 6th Fleet during an emergency in the Middle East, this time in Lebanon. Remaining off the Lebanese coast until September, she refueled over 200 ships as the U.S. 6th Fleet landed the U.S. Marine Corps and then stood by at the request of President Chamoun of Lebanon, in "Operation Blue Bat". From 1962 to 1964, "Mississinewa"s responsibilities were increased as she served as flagship of Commander Service Force, 6th Fleet.