The chief business of the new commission was the negotiation of a treaty with Prussia, advances toward which had first been made to Adams while at the Hague negotiating the Dutch loan, but before that treaty was ready for signature Adams was appointed by congress as Minister to the court of St. James, where he arrived in May, 1785. The English government, the feelings of which were well represented by those of the king, had neither the magnanimity nor policy to treat the new American States with respect, generosity, or justice. Adams was received with civility, but no commercial arrangements could be made. His chief employment was in complaining of the non-execution of the treaty of peace, especially in relation to the non-surrender of the western posts, and in attempting to meet similar complaints urged, not without strong grounds, by the British; more particularly with regard to the obstacles thrown in the way of the collection of British debts, which were made an excuse for the detention of the western posts. Made sensible in many ways of the aggravation of British feelings toward the new republic, whose condition immediately after the peace was somewhat embarrassing, and not so flattering as it might have been to the advocates and promoters of the revolution, the situation of Adams was rather mortifying than agreeable.

Meanwhile he was obliged to pay another visit to Holland to negotiate a new loan as a means of paying the interest on the Dutch debt. He was also engaged in a correspondence with his fellow-commissioner, Mr. Jefferson, then at Paris, on the subject of the Barbary powers and the return of the Americans held captive by them. But his most engrossing occupation at this time was the preparation of his "Defence of the American Constitution," the object of which was the justification of balanced governments and a division of powers, especially the legislative, against the idea of a single assembly and a pure democracy, which had begun to find many advocates, especially on the continent. The greater part, however, of this book—the most voluminous of his publications—consists of summaries of the histories of the Italian republics, which, by the way, was not essential to the argument.

Although it afterward subjugated the author to charges of monarchical and anti-republican tendencies, this book was not without its influence on the adoption of the federal constitution; during the discussion of which the first volume appeared. Great Britain not having reciprocated the compliment by sending a minister to the United States, and there being no prospects of his accomplishing any of the objects of his mission, Adams had requested a recall, which was sent to him in February, 1788, accompanied by a resolution of Congress conveying the thanks of that body for 'The patriotism, perseverance, integrity and diligence' which he had displayed in his ten years' experience abroad.

Immediately upon his arrival at home, Mr. Adams was re-appointed by Massachusetts as a delegate to the continental congress; but he never resumed his seat in that body, which was now just about to expire. When the new government came to be organized under the newly adopted constitution, as all were agreed to make Washington president, attention was turned to New England for a vice-president. This office was then held with much more regard than now. In fact, as the constitution originally stood, the candidates for the presidency and vice-presidency were voted for without any distinct specification as to rank, the second office falling to the person having the second highest vote. Out of sixty-nine electors, John Adams received the votes of thirty-four; and this being the second highest number, he was declared vice-president. The thirty-five votes were scattered upon some ten different other candidates.

By virtue of his new office he became president of the senate, a position not very agreeable to his active and leading temperament, being better fitted for debate; but one in which the close division in the senate, often resulting in a tie between the supporters and opponents of the new system, many times gave him a controlling voice. In the first congress, he gave no fewer than twenty deciding votes, always upon important organic laws, and always in support of Washington's policy.

Down to this time Adams had sympathized with Jefferson politically, with whom he had served both in congress and abroad. On the subject of the French revolution, which now burst upon the world, a difference of opinion arose between them. From the very beginning Adams, then almost alone, had argued that no good could come from that movement,—as the revolution went on and began to break out in excesses, others began to be of this opinion.

Adams then gave public expression to some of his ideas by the publication of his 'Discourses on Davila,' furnished to a Philadelphia paper, and afterward collected and published in one volume,—taking the history of nations, particularly Davila's account of the French civil wars, and the general aspects of human society as his texts.

Adams pointed out as the great springs of human activity,—at least in all that related to politics,—the love of superiority, the desire of distinction, admiration and applause; nor, in his opinion could any government be permanent or secure which did not provide as well for the reasonable gratification, as for the due restraint of this powerful passion. Repudiating that democracy, pure and simple, then coming into vogue, and of which Jefferson was the advocate; he insisted that a certain mixture of aristocracy and monarchy was necessary to that balance of interests and sentiments without which, as he believed, free governments should not exist. This work, which reproduced more at length and in a more obnoxious form the fundamental ideas of his 'Defence of the American Constitution,' made Adams a great bugbear to the ultra-democratic supporters of the principles and policy of the French revolutionists; and at the second presidential election in 1792, they set up as a candidate against him George Clinton, of New York, but Mr. Adams was re-elected by a decided vote.

The wise policy of neutrality adopted by Washington received the hearty concurrence of Adams. While Jefferson left the cabinet to become in nominal retirement the leader of the opposition. Adams continued, as vice-president, to give Washington's administration the benefit of his deciding vote. It was only by this means that a neutrality act was carried through the senate, and that the progress was stopped of certain resolutions which had previously passed in the House of Representatives, embodying restrictive measures against Great Britain, intended, or at least calculated, to counterwork the mission to England on which Mr. Jay had already been sent.

Washington being firmly resolved to retire at the close of his second presidential term, the question of the successorship now presented itself. Jefferson was the leader of the opposition, who called themselves republicans, the name democrat being yet in bad odor, and though often imposed as a term of reproach, not yet assumed except by a few of the more ultra-partisans. Hamilton was the leader of the federal party, as the supporters of Washington's administration had styled themselves.