The Lester S. Levy Collection of Sheet Music has 2 copies of the sheet music. The first, published in 1869, has the title I'LL REMEMBER YOU IN MY PRAYERS. The second, published in 1877, has the title I'LL REMEMBER YOU, LOVE, IN MY PRAYERS. In both, words and music are attributed to Will S. Hays.

The lyrics of the 1869 version (I didn't check the 1877 version) are nearly identical to the ones WYSIWYG posted above. I found only 4 small differences:

Chorus line 1:
Go where you will, on land or at sea,

Chorus line 3:
And at night, when I kneel by my bedside and pray,

Verse 2 line 2:
The love you have spoken for me,

Verse 3 line 1:
When heavenly angels are guarding the good,