I've come across an interesting note in the 4th edition of W.B. Whall's SEA SONGS AND SHANTIES (1920). It is on page two of that edition as an endnote following the song "Shenandoah". Whall says:

"This was not the only "song," by any means, which was used as a shanty. Dana told us long ago that one of the shanties used in his day was -

                         "Cheer up, Sam,
                         Don't let your spirits go down," etc.

which was made familiar to by the old Christy Minstrels."

Hugill says on page 562 of his SHANTIES FROM THE SEVEN SEAS (1961):

Another shore-song popular even in Dana's day aboard ship as a capstan song was the minstrel ditty "Cheer Up, Sam"."

If Lighter is right in his suggestion above, I'm wondering if Whall was Hugill's informant on this. But where did Whall (and Hugill) find "Cheer Up, Sam" in Dana?   I may have missed it, but I would be glad to have someone point me to it.