Found at https://www.loc.gov/resource/ihas.100010540.0  --

  Title: Marine's hymn
  Contributor Names: Offenbach, J. (composer), Tregina, A. (arranger),
  Phillips, L.Z. (lyricist)
  Created/Published: U.S. Marine Corps, 1919.

USMC Colonel Blake M. Wilson (now retired) accumulated more than 60
different sheet-music publications of The Marines' Hymn, all printed
between 1918 and 1981.  An article about Col. Wilson's research was
published in Leatherneck Magazine of Novemeber, 2014, available at
https://www.mca-marines.org/leatherneck/2014/11/marines-hymn 

Col. Wilson summarized the situation:  "While those Marines may have
figured out the origin, how the tune actually became what we know as
"The Marines' Hymn" was never discovered.  Even more of a mystery is
the source of the renowned lyrics."

The first half of the song is pure Offenbach but the second half is
a different composer.  I suggest that Matthew credit "Offenbach and
Anon." as composer.

I believe the lyricist credited as Thomas Holcomb is in error in the
Wikipedia article at https://en.wikipedia.org/wiki/Marines%27_Hymn 

Robbie Rhodes, MMD