After her Army career ended, Princess Matoika was transferred to the United States Mail Steamship Line for European passenger service in early 1921.

After that company's financial troubles resulted in her seizure, Princess Matoika was assigned to the newly formed United States Lines and resumed passenger service.

In March 1900 the Hamburg America Line (German: Hamburg-Amerikanische Packetfahrt-Aktien-Gesellschaft or HAPAG) announced the plans for 22 new ships totaling 150,000 gross register tons (GRT) at a cost of $11 million.

[28] Eventually, after offloading 500 short tons (450 t) of cargo from her front hold onto lighters called to the scene, ten steam tugs and power from Princess Alice's own engines freed the ship at 01:47 on 28 May, almost fifteen hours after running aground.

The man, headed to the spa town of Bad Nauheim in Hesse, had previously suffered a nervous breakdown and was under the care of a doctor on board the ship at the time he jumped overboard.

Leaving the neutral port in under 24 hours, the ship then rendezvoused with German cruiser Emden at Angaur before returning to the Philippines in early August and putting in at Cebu where she was interned.

[33] The newly renamed ship was taken to Olongapo City, 60 miles (97 km) north of Manila and placed in the drydock Dewey at Subic Bay where temporary repairs were made.

[36] Sailing at 18:30 the next day, Princess Matoika was accompanied by American transports Pastores, Wilhelmina, Lenape, Antigone, and Susquehanna, the British steamer Kursk, and the Italian Duca d'Aosta.

[41][42] After loading officers and men from the 29th Infantry Division on 13 June[32] Princess Matoika set sail from Newport News the next day with Wilhelmina, Pastores, Lenape, and British troopship Czar.

[43] Later that morning, the Newport News ships met up with the New York portion of the convoy—which included DeKalb, Finland, Kroonland, George Washington, Covington, Rijndam, Dante Alighieri, and British steamer Vauben—and set out for France.

He was cited for distinguished service as commander of the ship while "engaged in the important, exacting and hazardous duty of transporting and escorting troops and supplies through waters infested with enemy submarines and mines".

[52] On 23 September Princess Matoika departed New York with 3,661 officers and men accompanied by transports President Grant, Mongolia, Rijndam, Wilhelmina, British steamer Ascanius, and was escorted by battleship Georgia, cruisers Montana and North Carolina, and destroyer Rathburne.

[61] In March 1919 Princess Matoika and Rijndam raced each other from Saint-Nazaire to Newport News in a friendly competition that received national press coverage in the United States.

[62][63] Rijndam, the slower ship, was just able to edge out the Princess—and cut two days from her previous fastest crossing time—by appealing to the honor of the soldiers of the 133rd Field Artillery (returning home aboard the former Holland America liner) and employing them as extra stokers for her boilers.

[78] On 21 July Princess Matoika arrived in New York after a similar voyage with 25 war brides, many repatriated Polish troops among its 2,094 steerage passengers, and the remains of 881 soldiers.

[82] Near the end of the voyage, the athletes published a list of grievances and demands and distributed copies of the document to the United States Secretary of War, the American Olympic Committee members, and the press.

Outfitted for 350 cabin-class and 500 third-class passengers and at 10,421 gross register tons (GRT), Princess Matoika kicked off her U.S. Mail Line service on 20 January 1921, sailing from New York to Naples and Genoa on her first of three roundtrips between these ports.

[91] After repairs and a successful eastbound crossing, Princess Matoika had an encounter with an iceberg off Newfoundland while carrying some two thousand Italian immigrants on her first return trip from Italy.

[94] On the Matoika's third and final return voyage from Italy, begun on 17 May,[3] U.S. Customs Service agents at New York seized $150,000 worth of cocaine—along with valuable silks and jewels—being smuggled into the United States.

[99] In November, United States Lines announced that Princess Matoika would be replaced on the Bremen route in order to better compete with North German Lloyd, the liner's former owner, but that never came about.

[106] In October a Hoboken man, after securing a last-minute court order, was able to halt the deportation of his German niece on President Arthur; she was retrieved from the ship ten minutes before sailing time.

[110] Anchoring off Gravesend Bay on 30 October, President Arthur was one of fifteen passenger ships whose arrival in New York was timed to coincide with the opening of the November immigration quota period.

The dining room, large enough to seat 300 in a single sitting, was decorated in a Grecian theme,[126] and featured eighteen stained glass windows designed by San Diego architect Carleton Winslow.

During the journey, broadcasts of the City of Honolulu's orchestra, along with radio personalities and musicians from Los Angeles station KHJ, entertained both passengers and listeners on shore (while the ship was in range).

[130][133] Also sailing were movie star Laura La Plante and her husband, director William A. Seiter,[130] and, Western Auto founder George Pepperdine, who began a three-month tour of the Orient with his daughters.

On the return from Hilo, the liner would traverse the ʻAlalākeiki, the ʻAuʻau, and the Kalohi Channels, taking the ship between Maui and Molokai on the north and the islands of Kahoolawe and Lanai on the south.

[136] In June 1928 movie stars Norma Talmadge, Gilbert Roland, and Lottie Pickford began a Hawaiian vacation,[137] and on 28 July, Jane Addams, the founder of Hull House and a pioneer of the settlement movement, headed there as well.

[144] The next January, Herbert Hagerman, former Governor of New Mexico Territory; author Basil Woon, who had been doing research for a Hawaiian story; and aviation promoter and chewing gum magnate William Easterwood all sailed stateside on the ship.

[146] She also carried, in addition to passengers, cargo in both directions, transporting commodities, such as fertilizer and oil, to Hawaii,[147] and Hawaiian goods, like sugar and fresh and canned pineapple to the mainland.

Although aided by fireboat Leleiona and U.S. Navy submarine rescue ship Widgeon, firefighters were unable to bring the blaze under control quickly, and it spread to 100 short tons (91 t) of potash aboard the liner.