1900[June]        Patterson, J.E. "Sailors' Work Songs." _Good Words_ 41(28) (June 1900): 391-397.

This is an article on chanties that takes the approach, perhaps for the first time, of presenting a sort of ideal sequence of how the songs might figure into a voyage -- an idea used much by later presenters. The excerpt on "Leave Her Johnny" is as follows.

Here, completing our voyage, we will—for variety's sake—suppose her to have been an unpleasant vessel, and warp her into dock while singing:

Leave her, Johnny, leave her,
(Chorus) Leave her Johnny! [Pull.]
Now we'll sing you a farewell song, 

Leave her, Johnny, leave her! [Pull.]

Leave her, Johnny leave her,
Leave her, Johnny!
Pack your bags and go on shore,
For it's time for you to leave her!

Leave her, Johnny, leave, her
Leave her, Johnny

For the grub was bad, and the wages low.
So it's time for you to leave her!

Leave her, Johnny, leave her,
Leave her, Johnny!
For the mate's a terror, and the "old man"'s worse.
So it's time for you to leave her!

So, that's 4 references to the song in the 19th century.