Three letters : written, and originally published, under the signature of A South Carolina planter. The first, on the case of Jonathan Robbins; decided under the twenty-sixth article of the treaty with Great-Britain, in the District Court of the United States, for South Carolina. The second, on the recent captures of American vessels by British cruisers, contrary to the laws of nations, and the treaty between the two countries. The third, on the right of expatriation. / By Charles Pinckney, Esquire, senator in Congress, for South-Carolina. ; To which is added, an appendix, containing sundry documents concerning Jonathan Robbins.