Composed by a white hymnist, this easily learned little song has been adapted by both blacks and whites. Unlike many hymns, it uses the old two-line verses common in Negro spirituals and a repetitive chorus, making it easy to add to and revise.
In answer to PK, these songs are all based "on de Book" in some way, but there are so many that they must be classified in some way to make finding and comparing them easier. The general heading is religion, but divisions such as hymns (more or less formally composed), spirituals (Negro songs composed during the slavery period and in succeeding decades but in the same forms), gospel (white and black), (religious) blues, etc. are very useful, if sometimes overlapping.
See African-American Spirituals Permathread and other threads mentioned there.