It appears that the lyrics were written by neither. Henry
Burleigh adapted Dvorak's composition into the song, but William
Arms Fisher wrote the lyrics. Actually, Dvorak incorporated the
tune of the Negro spiritual "Goin' Home" into his New World
Symphony. "Goin' Home" existed before Dvorak wrote his symphony.
Dvorak lived in the US for a few years, and found himself very
drawn to this melody, so he used it.