Grovel, grovel. I'm wrong its not a 1st WW Song. I've found this. It might help a bit
In 1897, he was just 24 years old, Morse formed the Morse Music publishing company, and published a hit song (written by Will Cobb and Paul Barnes) of the Spanish-American War, "Goodbye, Dolly Gray". His wife, writing under the pseudonym of D.A.Esrom, contributed the lyrics to the song, which was published under the title of "Hail, Hail, The Gang's All Here".
Regards
John