My next Hi-lo reference is as follows:

1857        Long, John Dixon. _Pictures of Slavery in Church and State._ Third edition. Philadelphia: John Dixon Long.

This is an abolitionist text. Reverend Long (b. 1817) grew up and spent most of his life in Maryland, and his father was a slave-holder, so his experiences probably come from there. Exact time unknown, as he is speaking in generalities.

The songs of a slave are word-pictures of every thing he sees, or hears, or feels. The tunes once fixed in his memory, words descriptive of any and every thing are applied to them, as occasion requires. Here is a specimen, combining the sarcastic and the pathetic. Imagine a colored man seated on the front part of an ox-cart, in an old field, unobserved by any white man, and in a clear loud voice, ringing out these words, which wake up sad thoughts in the minds of his fellowslaves :

"William Rino sold Henry Silvers;
            Hilo! Hilo!
Sold him to de Gorgy trader;
            Hilo! Hilo!
His wife she cried, and children bawled,
            Hilo ! Hilo !
Sold him to de Gorgy trader;
          Hilo! Hilo!

So this is the first I have to actually use the rendering /hilo/. If one compares it to the "Johnny Come Down de hollow," one finds similar solo lyric ideas, i.e. about being sold off to Georgia. Those ideas also turn up in other songs strains which may or may not be related (e.g. Shallow Brown). I find it notable here that the very first two Hi-lo reference both have them.