The verse with 'rough and steep' is rhymed differently in other versions. In one from Odum and Johnson, 1925, "The Negro and His Songs," posted in thread 23495, the verse is:
I know dark clouds'll gather 'round me,
I know my road is rough and steep;
Yet there bright fields are lying just before me,
Where God's redeemed their vigils keep.
'...their vigils keep' is the line in Bever's Christian Songster, 1858, and is the one found in "The Sacred Harp," Wayfaring Stranger
The Cyberhymnal has "Where God's redeemed shall ever sleep" as the last line of that verse. I Am a Poor

The DT version, where the line reads "steep and rough,' comes from Burl Ives, p. 182-185, "The Burl Ives Songbook," and Silber, p. 352, "Folksinger's Wordbook."

Not certain when this old white camp meeting hymn was first used by African-Americans; they sang it in the 1880s. The first great camp meeting was held in Kentucky in 1801, and this song appeared in print in 1816 in Kentucky; one may speculate, without verification, that the song was sung at this first camp meeting.