In 1837, Mr. Wheaton was raised by President Van Buren to the rank of Minister Plenipotentiary and Envoy Extraordinary; and we cannot forbear remarking, that after the opposition which—although never a violent party man—he had in previous years shown Mr. Van Buren, it is most honorable to the latter, that no feeling of rancor or pique, withheld him from making a nomination which he felt the public services of his former opponent to deserve.
In 1836, he published, in England and in the United States, his "Elements of International Law," and in 1846 republished it in this country with numerous additions. In 1841 he wrote in French, "Histoire du Progrès du Droit des Gens depuis la paix de Westphalie," which obtained a mention honorable from the French Institute. This work was published in French at Leipsic, 1844, and afterwards in New-York, under the title of "History of the Law of Nations." Competent judges have spoken of it as the best work of the kind ever written; Mr. Reddie and Mr. Manning in Great Britain, Baron Gagern in Germany, and the enlightened and accomplished Minister of the King of Sardinia, Marquis d'Azeglio, have all awarded high praise to it. By diplomatists, it is considered an invaluable book of reference; by British statesmen, it has several times been quoted in Parliament, and there can be no exaggeration in saying, that it has entitled the author to a lasting reputation in the Old World.
In 1840, Mr. Wheaton had the misfortune to lose his eldest son, a lad of great promise, who died after a few days' illness in Paris, where he was at school. From that moment, all the father's hopes centred in Robert, his only remaining son. Of the latter, this is not the place to speak fully; but we cannot forbear to say, that he lived long enough to realize the fondest anticipations of his parents, and that his early death, at the age of twenty-five years, will ever be a source of regret to all who knew him. He died on the 9th of October, 1851, only three years after his father.
In 1843, he was made a corresponding member of the French Institute, in the section of Moral and Political Sciences. This nomination increased the pleasure he felt in visiting Paris, which he did, whenever his official duties would permit. In the literary and political circles of that great capital, he found the stimulus which every mind like his requires, and of which, he felt the want in Berlin, where men of letters and savans do not mix in the court-circles, which his official position compelled him frequently to attend. He knew most of the eminent statesmen and politicians of France; he was particularly well acquainted with M. Guizot, for whose character and talents he entertained the highest respect, and with M. Thiers, the charm of whose conversation he admired no less than his works, He also enjoyed the opportunity he had in Paris of meeting his countrymen, of whom comparatively few visited Berlin. Nor did he neglect when there, to transmit to Government such information respecting the general state of Europe, as his long residence abroad, and his relations with the leading men in several of its countries, enabled him to collect. In the ten years during which his mission to Berlin lasted, scarcely a week elapsed without his addressing a dispatch to Government. These dispatches are extremely interesting, both from the variety and extent of information they contain concerning the political and commercial state of Prussia, and the picture they present of Europe and of European governments, and, if ever published, will form a valuable addition to the history of American and European diplomacy.
In many respects, Mr. Wheaton was peculiarly well qualified for diplomatic life. His knowledge of international law, the soundness of his judgment, the calmness and impartiality with which he could look at the different sides of a question, his gentle and forbearing disposition, his amiable and conciliating manners, were all in his favor. To these advantages, he added the purest integrity, and the highest sense of the duties and responsibilities attached to the profession he so long followed. In the speech made at the public dinner offered him in New-York, on his return to his native country after an absence of twenty years, he said, and this was the true expression of his feelings on the subject: "You will excuse me for remarking that the mission of a diplomatic agent is, or ought to be, a mission of peace and conciliation; and that nothing can be further removed from its true nature and dignity, than intrigue, craft, and duplicity; qualities too often, but in my opinion, erroneously, attributed to the diplomatic character. At least, it may I believe be confidently asserted, that the ablest public ministers, and those who have most effectually advanced the honor and interest of their country, have been those who were distinguished for frankness, directness, and a strict regard to truth."
The amount of business which devolved on him during his mission to Berlin, independent of the negotiations for a commercial treaty with the German Customs-Union or Zollverein, can hardly be estimated by reading his dispatches only. Not a week elapsed without his receiving letters from different parts of Germany and the United States, asking for advice with regard to emigration, or to the disposition of property left by friends in America or in Germany, and all requiring immediate attention. But notwithstanding these demands upon his time, he did not neglect the pursuits of literature. In 1838 he published, jointly with Dr. Crichton, the volumes entitled "Scandinavia," which form a portion of the Edinburgh Family Library; and in 1842, and the succeeding years, wrote a number of interesting letters addressed to the National Institute at Washington, which were published in the columns of the National Intelligencer.
In 1844, he was named Member of the Academy of Sciences at Berlin, and we must not omit to mention, that he was the only foreign diplomat to whom the honor had then been awarded. With Raumer and Ranke, with Ritter, the celebrated geographer, Encke, the astronomer, he was of course acquainted; Savigny, Gans, and Eichorn, he knew well; and with Alexander von Humboldt he was on the most friendly and familiar terms. Count Raczynski, whose work on "Modern Art," has made his name known in this country, and whose fine gallery is to amateurs of painting one of the chief objects of interest in Berlin, was also his intimate friend. With Bunsen, one of the most agreeable as well as intellectual men in Germany, whose diplomatic duties kept him absent from Berlin, he passed many delightful hours in Switzerland, and in London. All his colleagues in Berlin met him on the most friendly terms; but the Russian, French and English ministers were those whose company he most enjoyed, and who perhaps entertained for him the most cordial friendship. The two latter gave him their entire confidence, often showing him their dispatches, and freely discussing with him the interests of their respective governments.
It was in the spring of 1844, that the negotiations with the Zollverein, with which Mr. Wheaton had been charged, and which the various interests of the nineteen different states which it then included, had protracted, drew to a close. On the 25th of March he signed a convention with Baron Bulow, the Prussian Minister of Foreign Affairs, of whose enlightened and liberal views he always spoke in high terms. This treaty, to the accomplishment of which he had devoted all his energies during several years, and which he fondly hoped would prove satisfactory to Government and the country, was rejected by the Senate. It is hardly necessary to say, that he felt this disappointment deeply.
In 1846, he was recalled by President Polk, and on the 22d July had his farewell audience of the King of Prussia, by whom he had always been treated with marked distinction and courtesy. He went to Paris to pass the ensuing winter, during which he read to the Academy of Sciences a paper on the Schleswig-Holstein question, which is still unpublished. In May, 1847, he returned to his native land. A public dinner, to which we have already alluded, was given him in New-York, where so much of his early life had been spent, and where he had first distinguished himself; a dinner was also offered him in Philadelphia, but this, circumstances compelled him to decline. The city of Providence requested him to sit for his portrait, to be placed in the hall of the City Council, "as a memorial of one who shed so much honor on the place of his nativity." It is interesting to mark the contrast between this portrait, which was painted by Healy, and one painted by Jarvis nearly thirty years before. Though the countenance has lost something of the animation of youth, and the eyes have no longer the fire which flashes from the portrait of Jarvis, the head has gained in intellectual expression, and the brow wears that air of thoughtful repose, the mouth that pleasant smile, familiar to those who knew him in his later years.
In September, 1847, he delivered an address in Providence, before the Phi Beta Kappa Society, the subject of which was the Progress and Prospects of Germany. This was the last public occasion on which his voice was heard. The chair of International Law at Harvard University, to which he had been called, on his return home, he never lived to fill. His health gradually failed, and on the 11th of March, 1848, he breathed his last.