Minnekahda was in the fleet of the Atlantic Transport Line, which was part of the International Mercantile Marine Company.

[2] Harland & Wolff had used this arrangement first on Laurentic (1908) for White Star Line, and most notably on the three Olympic-class ocean liners.

In the predawn hours of 23 July, the United States Navy submarine USS N-3 was on the surface in the Atlantic Ocean, charging her batteries in calm, hazy weather with bright moonlight, when she suddenly sighted one of the ships of the convoy at 02:55 at a range of only 1,800 yards (1,650 m).

As N-3 continued to flash the recognition signal by blinker light, N-3′s commanding officer hailed Minnekahda, calling out "Don't fire, this is an American submarine!"

At that instant, one of Minnekahda′s guns fired a 6-or-7.5-inch (152 or 191 mm) round (according to different sources),[8][9] and the shell hit N-3 forward at the waterline, failing to explode but inflicting considerable damage and causing leaks.

N-3 had suffered no crew casualties, but Minnekahda′s unexploded shell was found in N-3′s forward superstructure, and N-3′s torpedo compartment was partially flooded.

After pumping 2,800 US gallons (2,331 imp gal; 10,599 L) of diesel fuel overboard to lighten herself forward, N-3 proceeded to port on the surface under her own power.

[9] Minnekahda repatriated Allied troops after the armistice with Germany that ended World War I on 11 November 1918.

On the voyage one U.S. soldier aboard Minnekahda died of pneumonia, which he caught as a secondary infection after contracting the Spanish flu.

Atlantic storms slowed the convoy by 36 hours, and Lapland and Minnekahda reached New York on 5 December 1918.

[11] On 16 January 1920 she left London on her final trooping voyage, crossing the Atlantic via Halifax, Nova Scotia, Canada, to New York City.

[13] Bethlehem Steel at Fore River Shipyard in Quincy, Massachusetts refitted the ship[1] at a cost of $700,000 to carry civilian passengers.

[13] Minnekahda's first voyage as a passenger liner was another charter to American Line for a single round trip.

[1] When Minnekahda docked in New York on 26 July 1922, a squad of 30 US Customs personnel searched her and inspected her disembarking passengers and crew.

Her Quartermaster was found in possession of undeclared diamonds and other jewelry worth a total of $10,000, and was arrested on suspicion of smuggling.

In March 1925 Atlantic Transport Line announced that it would reduce Minnekahda's passenger accommodation to 750 berths, all tourist class.

The company changed her European port of departure from Hamburg to London, and announced that she would now bring British tourists to the US.

[20] On 4 and 5 December 1925 on a westbound voyage from London to New York, Minnekahda encountered a "hurricane-force" storm that tore away 15 feet (5 m) of railing from the after part of her deck.

The Ship's Clerk said that Customs officers entered his cabin in his absence, threw his two suitcases on the floor and broke the locks.

[22] In 1929 Minnekahda began the tourist season by leaving New York on 6 April, bound for London via Boulogne.

[23] In August 1929 the IMM reported that its business was thriving, thanks to the increasing popularity of tourist class travel.

It tore off part of the deck railing from her starboard side, damaged some of her davits and carried away several of her ventilators.

One of the boats, commanded by her Third Officer, rescued the young woman and took her back aboard, where she was admitted to the ship's hospital.

General Electric transmitted a copy of the Union-Star newspaper of Schenectady by wireless to Minnekahda and the United States Lines ship America.

Throughout her ten-year passenger career she had the same Master, Captain Johan Jensen, who was born in Denmark and became a US citizen.