I have a "Canadian Soldiers' Songbook" published during the Great War by the YMCA which has "The Anglo-American Anthem", the first verse is verse 1 of "God Save the King" verse 2 is the first verse of "My Country 'tis of Thee" and the third verse runs;

"Two Empires by the sea,
Two peoples great and free,
One anthem raise.
One race of ancient fame,
One tongue, one faith we claim,
One God whose glorious Name
We love and praise."

maybe not singable these days, but worth mentioning I think.

Walrus.