LP - Memorial for the unknown dead

A monument in Loudon Park National Cemetery, an appendix to the far larger Loudon Park Cemetery housing the remains of Civil War veterans, erected by the Women's Relief Corps Auxiliary to the Grand Army of the Republic. An inscription on the back reads:

"BUT THERE UPON THE SODDEN EARTH HE BIDES
HIS LAST LONG SLEEP, TO SLEEP UN-NAMED, UNKNOWN
UNTIL GOD'S ANGEL ON THE WHIRLWIND RIDES
TO CLAIM HIS OWN."

Apparently that comes from a poem by one Kate Brownlee Sherwood, the "Poetress of Congressional Circle," however I can't seem to find what, if any, publication it was found in.