Why do certain historians – British and American – write history in the passive voice? Walter Stahr’s prose is cluttered with ofs and bys that result in historical congestion. Why write “In words drafted by Jay, Congress …” Sentences should have a stronger beat: “In Jay’s words, Congress …” No wonder such history is slow going; it has no pickup: “Not long before this time, a British fleet had defeated …” Please get on with it! “A British fleet had just defeated.”

This sluggishness is a pity, since Mr. Stahr has written a valuable book in “John Jay: Founding Father” (Hambledon & London, 496 pages, $29.95), the first biography of John Jay to appear in 70 years. As president of the Continental Congress, secretary of foreign affairs, first chief justice of the Supreme Court, and governor of New York – not to mention serving on numerous other governmental missions – Jay commands our attention. So why so few biographies of this founding father?

Jay destroyed a good deal of his personal correspondence, and his papers as governor were destroyed in a fire. Not as flamboyant as his New York colleague Alexander Hamilton, Jay was ambitious but not really a fame-seeker. Jay also had a habit of telling unpleasant home truths. He wanted the states to pay up after the Revolutionary War – that is, to honor the treaty with Britain that committed U. S. citizens to satisfy British claims for damages. Otherwise, Jay argued, America had no prospect of removing British forts from American soil (stipulated under another part of the treaty).

Slowly – too slowly – Mr. Stahr builds an impressive portrait. Early on, Jay realized that his new nation needed a strong national government. Jay realized there had to be a central government or the United States would remain a weak power rather like the European Union of today – to use Mr. Stahr’s analogy. Much of the language he drafted for the Continental Congress during the Articles of Confederation period made its way into the U.S. Constitution.

In the most important matters, Mr. Stahr is a superlative biographer, reporting the criticisms made of his subject and then showing why, in most cases, Jay knew better than his contemporary critics and later historians. For example, Jay held up peace negotiations with Britain because he insisted on recognition of an independent United States as a precondition to treaty discussions. This gave Britain two months to fortify itself and cause dissension between the United States and its French ally. But without the Jay delay, could the United States have obtained better terms? Mr. Stahr doubts it, and points out that most Americans, including Hamilton and Jefferson (the latter philo-French) thought Jay had obtained a good deal.

What Mr. Stahr has to say about Jay’s work as a spymaster during the Revolutionary War is fascinating. (The CIA has honored him as the nation’s first counterintelligence chief.) Jay’s job, in his biographer’s words, was to neutralize Tories. During a period when Washington was losing every battle, Jay ferreted out Loyalists in New York and, in some cases, deported them. Jay the man, I learn from Mr. Stahr, had no grudges against Tories. He was just doing his job and hoped – as he told more than one Tory – that after the war they could resume amicable relations.

That Jay was a lawyer is profoundly important. He believed in carefully worded contracts and was scrupulous in showing the Continental Congress, for example, that it could not hope to act as a national governing body if it did not scrutinize the laws of the several states and ascertain that they were working in harmony. As Mr. Stahr repeatedly shows, Jay’s work established the necessary ground on which the U. S. Constitution was built.

The few extant letters of a personal nature suggest that Jay’s wife, Sarah, was a lively and shrewd partner. She is one of those gustatory Americans. Even wretched Spain, where her husband was attempting to enlist king and country on the American side, provided her with entertainment. After describing how she had to purchase a broom to sweep out “several loads of dirt” in their village inn room, which included “two or three thousand fleas, lice, bugs etc.,” she relates they then had to settle down for the night “serenaded” by the tinkling bells of mules in the next room.

Fortunately Sarah was one of those wives who knew how to amuse herself. Another kind of spouse would have said John Jay was no fun. He rarely noticed his surroundings and left almost no record of what he thought of Madrid or Paris. He was all business and apparently did not wish posterity to see the whole man. A biographer can only wail at the result.

Mr. Stahr does his best, I presume, in squeezing the data of every last drop of intimate details. Jay seems to have been an ardent man, judging by the intensity of his friendship with William Livingston, an early law partner who apparently rebuffed Jay’s desire for a closer relationship. What passed between Jay and Livingston is beyond speculation, and Mr. Stahr wisely prefers just to quote one of Jay’s evocative epistles to Livingston.

This speaks of an intimacy “firm and indissoluble, which once entered on, ought ever to be preserved inviolable.” When Jay then continued to write to his friend about a “connection of the most delicate nature, a connection replete with happiness and productive of very extensive advantages,” Livingston, in Mr. Stahr’s words, “found these warm words too much, and suggested that they write on other themes.”

This biographer is able, however, to show Jay was a key participant in the creation of the new nation. He was calm and judicious and got along well with personalities as different as Samuel Adams and Alexander Hamilton. This is a steady and perceptive – if not brilliant – biography, an important contribution to understanding the brilliance of one of those who made this country.