During this protracted career in foreign countries, charged with responsible negotiations, he was not lost in the toils of office, or in the allurements of court life. He was always a student. At Copenhagen he prepared his "History of the Northmen, or Danes and Normans, from the Earliest Times to the Conquest of England by William of Normandy." This was published in 1831, both in England and in America. In 1844 it was much enlarged, and translated into French. At the time of his death he was occupied in preparing another edition. In 1838 he contributed to the Edinburgh Cabinet Library a portion of the volumes entitled "Scandinavia." By these works he earned an honorable place among our historical writers. His History of the Northmen preceded, in time, the productions of Bancroft and Prescott, which have since achieved so much renown.
From literature he passed again to jurisprudence, where he has won his surest triumphs. His "Elements of International Law" appeared in London and the United States in 1836, and again in 1846, much enlarged. This was followed by a "History of the Law of Nations in Europe and America, from the Earliest Times to the Treaty of Washington," which first appeared in French, at Leipsic, in 1841, under the title of Histoire des Progrès du Droit des Gens en Europe depuis la Paix de Westphalie jusqu'au Congrès de Vienne, avec un Précis Historique du Droit des Gens Européen avant la Paix de Westphalie. This was originally written for a prize offered by the French Institute. The question proposed was, Quels sont les progrès qu'a fait le droit des gens en Europe depuis la Paix de Westphalie? It was bold and honorable in Mr. Wheaton to venture in a foreign tongue the discussion of so great a subject. The Greek of Cicero excited the admiration of the rhetoricians at Rhodes and Athens, and the French of Gibbon was in harmony with his own swelling English style; but Mr. Wheaton, whether in French or English, is commended by matter rather than manner. On this account he was at disadvantage before the polished French tribunal. His effort received what was called mention honorable; but the prize was awarded to a young Frenchman, whose production has never seen the light. An impartial public opinion has awarded our countryman another prize more than academic. The same work in English, much enlarged, is now an authority.
Besides these classical treatises, Mr. Wheaton published an able and thorough Inquiry into the Validity of the Eight of Visitation and Search, particularly as recently claimed by Great Britain. Here he upheld the views of the American government. The acknowledged weight of his opinion in the science of law gave to his conclusions commanding influence.
On his recent return to this country, he was welcomed with many manifestations of regard, both public and private. Wherever he appeared, he was a favored guest. At the last Commencement of Brown University, he delivered the Address before the Phi Beta Kappa Society. His subject was Germany. The various departments of thought and conduct, which have been successfully occupied by the "many-sided" mind of that country, were sketched with singular ability. His voice was feeble, and, as he spoke, large numbers of the audience drew near the pulpit, filling the adjacent aisles, and standing in respectful attention, that they might follow his learned discourse.
Such were the important and diversified labors of his valuable life. Without any adventitious aids of fortune, or special favor, he achieved eminent place in the civilized world. By virtue of his office he lived as an equal among nobles and princes, while his rare endowments opened to him at will the fraternities of learning and science. And yet his qualities were not those of the courtier. Nor did any heaven-descended eloquence lend fire to his conversation or style. Both were simple, grave, reserved, like his manners, attractive rather from clearness and matter than from brilliancy or point.
His career abroad as Diplomatist was one of the longest in our history,—longer even than that of John Quincy Adams. It was not his fortune to affix his name to any treaty, like that of 1783, which acknowledged our Independence, or that of Ghent in 1814, which restored peace to England and the United States. But his extended term of service was filled by a succession of wise and faithful labors, which rendered incalculable good to his own country, while they impressed his character upon the public mind of Europe. His negotiation with Denmark was important. More important still was his careful management of our national interests in connection with the German Zollverein. Besides these conspicuous acts, with which all are familiar, there is his long and constant correspondence with the Department of State at Washington, which is known to comparatively few, although of exceeding merit.
It was his habit, contrary to the usage of many American ministers, by regular authentic communications, to keep the Government at home informed with regard to the position of foreign nations, as observed by him. All the matters which prominently occupied the Continental nations during his residence abroad, particularly those two disputes known as the Belgian question and the Egyptian question, which seemed for a while to fill the firmament of Europe with "portents dire," were discussed in these despatches with instructive fulness. These may be found in the archives of his legation, and in the Department of State at Washington, "enrolled in the Capitol," where they will be studied by the future historian.
His familiarity with the Law of Nations, from his position as a diplomatist, was enhanced by mature and thorough study. For this he was prepared by training at the bar, the influence of which may be discerned in some of his writings. He was master alike of its learning and its dialectics. It happened in Berlin that he was called to defend the rights of ambassadors against an injurious usage established or recognized by the Prussian government. All who have read his paper on this occasion will attest the force and sharpness of his unanswered argument. Strange that this task should have devolved upon an American minister! Strange that the privileges of ambassadors should have found their defender in a Cis-Atlantic citizen! His defence excited the attention of the diplomatic body in Europe. Copies were transmitted to the different courts, where, as I have understood, it was discussed, and generally, if not universally, sanctioned.
Justly eminent as a practical diplomatist, his works derived new value from the position of their author, while even his official rank was aided by his works. His was a solitary example in our age, perhaps the only instance since Grotius, of an eminent minister who was also an expounder of the Law of Nations. His works, therefore, are received with peculiar respect. Already they have become authorities. Such they are regarded by the two British writers who have since appeared in this field, Mr. Manning and Mr. Reddie. The former, in his excellent Commentaries, refers to Mr. Wheaton's work on the Elements of International Law as "certainly the best elementary book on the topic that exists";[237] while Mr. Reddie announces that "this work, although not by a British author, was certainly, at the date of its publication, the most able and scientific treatise on International Law which had appeared in the English language."[238] It is admitted that the method is superior to that of Martens, Chitty, Schmalz, or Klüber.
It cannot be disguised that his two works in this department are remarkable for careful statement and arrangement, rather than for that elegance, or glow, or freedom of discussion, by which the reader is carried captive. His Elements afford the best view yet presented of the Law of Nations, as practically illustrated in the adjudged cases of England and the United States, and in recent diplomacy. But we miss in them the fulness and variety of illustration which characterize some of the earlier writers, and especially that genial sentiment which interests us so constantly in Vattel. The History, which first appeared in French, is not less important than the Elements. Here the field is more clearly his own. This work supplies a place never before filled in the literature of the English language, if in that of any language. To all students of jurisprudence, nay, more, to all students of history, who ascend above wars and battles to the principles which are at once parent and offspring of events, this account of the Progress of the Law of Nations is an important guide.