There's been almost no discussion on Mudcat (or anywhere else) of this American forebitter printed by Joanna C. Colcord in "Roll and Go" (1924) and set to the "Derry Down" tune now seemingly inseparable from "The Dreadnought."

The bark "Dom Pedro II" is mentioned in the shipping news of the New York Herald (June 29, 1860), p 10, having arrived in Boston "from Bahia, via Holmes' Hole."

The final mention I've found of "Dom Pedro II" is in the Savannah Morning News (June 24, 1904), p. 11. The previous day she'd been cleared or Baltimore from Key West.

The NY Herald (Dec. 20, 1861), p. 8, notes the Pedro's arrival in Kanagawa on Sept. 23. On Sept. 23, 1865, (acc. to the Herald of Nov. 1), she arrived in Hong Kong from Singapore.

I haven't noted any arrival in Shanghai, as in the song, but then I haven't searched everywhere.   Dom Pedro, however, clearly made voyages to the Far East in the 1860s.

Trivia:
The Washington Times (May 18, 1915), p. 7. mentions that one of "Pedro's" old captains was H. H. Kiehle, of Baltimore, who at one time had also commanded the (handy, bandy) bark "Campanero." At the time of the article, only four American windjammers (not including Dom Pedro II) were still rounding the Horn.

Although the DT credits Colcord as its source of the song, it includes a "hi derry, ho derry" chorus that is *not* in Colcord.

What's more, the tune is different.