usslouisville

with her neutral American signage for the u-boats

see note under

The two liners were sister ships.
"For many years, SS St. Louis was prominent as a passenger liner between New York and Liverpool. On 17 March 1917, she was furnished an armed guard of 26 United States Navy sailors and armed with three 6-inch guns, to protect her from enemy attack as she continued her New York-to-Liverpool service."
en.wikipedia.org/wiki/SS_St._Louis_(1894)
en.wikipedia.org/wiki/USS_Saint_Paul_(SP-1643)

Other Bain photos

See notes under

The caption on the original photo denotes SS St. Paul, and her sister ship SS St. Louis in parentheses (presumably to use the same stock photo when illustrating either ship). After looking at the larger version of this photo, and squinting a bit, it appears that this is actually a photo of the SS St. Louis.

this photo is used in Wiki as St Louis en.wikipedia.org/wiki/SS_St._Louis_(1894) SS St. Louis, a transatlantic passenger liner built by the William Cramp & Sons Building & Engine Company, Philadelphia, Pa., was launched on 12 November 1894; sponsored by Mrs. Grover Cleveland, wife of the President of the United States; and entered merchant service in 1895, under United States registry for the International Navigation Co., of New York with her maiden voyage between New York and Southampton, England. She was acquired by the United States Navy during the Spanish–American War and commissioned under the name USS St. Louis in 1898, and again during World War I under the name USS Louisville (ID-1644) from 1918 to 1919.[Note 1] After she reverted to her original name in 1919, she burned in 1920 while undergoing a refit. St. Louis was scrapped in 1924 in Genoa. Wiki has a photo of St Paul but no apparent article en.wikipedia.org/wiki/File:SS_St._Paul.jpg

In Spring/Summer 1914, both St. Louis and St. Paul served as passenger liners on transatlantic routes to England. According to Shipping News in NYT.