Written…as a Christian good-bye, it was called forth by no person or occasion, but was deliberately composed as a Christian hymn on the basis of the etymology of "good-bye," which is "God be with you." The first stanza was written and sent to two composers-one of unusual note, the other wholly unknown and not thoroughly educated in music. I selected the composition of the latter, submitted it to J. W. Bischoff-the musical director of a little book we were preparing-who approved of it, but made some criticisms, which were adopted. It was sung for the first time one evening in the First Congregational Church in Washington, of which I was then the pastor and Mr. Bischoff the organist. I attributed its popularity in no little part to the music to which it was set. It was a wedding of words and music, at which it was my function to preside; but Mr. Tomer should have his full share of the family honor.

-- Jeremiah F. Rankin, as quoted by Ira D. Sankey

Source: The Cyberhymnal