SS Corsican in World War I

I'm trying to verify information in my grandfather's journal: He wrote that he sailed from Hoboken, New Jersey to Southampton and on to La Havre in June of 1918 on the Corsican, which he states was a "British ship." I know that almost half of the U.S. troops who fought in World War I sailed to Europe on British ships, but the history of the Corsican here /ships/cors2/ isn't clear about whether it was carrying U.S. troops at this time. Any information will be greatly appreciated - I'm in the process of transcribing his journal and would love to have this to fill it out.