By R. Kent Newmyer, Cambridge University Press, Cambridge and New York, N.Y., 226 pages, $28.99.

American history has its full share and then some of illustrious (or infamous) characters. High on any list of such personages belongs the name of Aaron Burr. A combat veteran of the Revolutionary War, a brilliant and successful New York trial lawyer and the country’s third vice president, Burr gained notoriety by killing Alexander Hamilton in a duel at Weehawken, N.J., in 1804. In “The Treason Trial of Aaron Burr,” Professor Kent Newmyer of the University of Connecticut tells in detail how his subject escaped the hangman’s noose in a proceeding that has left its mark to this day on our constitutional law.

The trial took place in the U.S. Circuit Court in Richmond, Virginia, in the summer of 1807. Chief Justice John Marshall, sitting with a jury in his capacity as circuit judge, presided. The case attracted national attention, packed the courtroom day after day and brought together an all-star cast of Virginia’s (and the nation’s) most prestigious trial counsel.

The bitterly contested trial, according to the author, “often verged on chaos.” At issue was the purpose of expeditions that Burr, acting out what Newmyer calls “audacity, arrogance and [a] sense of frustrated entitlement,” conducted to the western United States in 1805 and 1806. He assembled and partially armed a force that never exceeded 100 men. At the trial the defense contended that Burr planned to help liberate Mexico (then including Texas) from Spanish occupation. The prosecution alleged that Burr had in mind separating the western states from the Union.

Throughout the book, the author emphasizes the part played by President Thomas Jefferson, who, he maintains with documentary support, took “personal charge of” and “micromanaged” from the White House the prosecution in Richmond. He imputes to Jefferson “a complex mixture of impetuosity, vindictiveness and self-righteousness.” Jefferson, he claims, never forgave Burr for not conceding the presidential election of 1800, which a tie in the Electoral College between Jefferson and Burr had relegated to the House of Representatives. (Burr then served for four years as Jefferson’s vice president.)

In a report to Congress on Jan. 22, 1807, Jefferson, usurping, says the author, the functions of grand jury, judge and trial jury, pronounced Burr guilty of treason in his alleged effort to break up the Union by force of arms. “[H]is guilt,” stated the President, “is placed beyond question.”

Time and again Newmyer challenges the propriety of this prejudgment. As a further complication, Newmyer stresses the antagonism that prevailed between Jefferson and Marshall. It went back to Marshall’s landmark opinion in Marbury v. Madison (1803), an assertion of nationalism that contravened Jefferson’s fervent belief in states’ rights. Marshall and Burr, moreover, had been comrades in arms at Valley Forge, a fact that caused Jefferson to suspect the chief justice of favoritism toward a defendant of whose guilt Jefferson was irrevocably convinced.

Treason is the only crime that the Constitution defines. The offense is limited, according to Section 3 of Article III, to “levying War against [the United States], or in adhering to their Enemies, giving them Aid and Comfort.” The author explains this specificity as the Founders’ safeguard against the doctrine of “constructive treason,” which had been used in colonial days to suppress political dissent. Paradoxically, argues Newmyer, the prosecution in the case against Burr resorted to that very doctrine.

What the author calls “the grand climax of the trial” came on Aug. 31. Marshall, after prolonged deliberation, issued a lengthy opinion granting a defense motion to exclude a great part of the prosecution’s evidence until it proved the “overt act” essential to the “levying war” requirement of Article III, Section 3. The opinion, among other things, sett forth a definition of treason “worked to discourage prosecutions under that clause” and “laid the cornerstone of American treason law.”

On Sept. 1, the next day, the jury returned a verdict for the defendant. Instead of finding him “not guilty,” however, their verdict read, “[N]ot proved to be guilty under this indictment by any evidence submitted to us.” This “Scotch verdict” broadened the popular feeling that Burr had gotten away with treason. Hard to believe today, it also intensified calls for Marshall’s impeachment, which had begun with Marbury v. Madison. (Jefferson, embittered by the decision of Aug, 31, may have worked with his friends in Congress in an effort to bring about impeachment.)

Within a few days, Burr went on trial again, this time for violation of the Neutrality Act of 1794 in promoting and preparing for war with Spain. As a defense, he alleged that his plans for hostile action were to take effect only in the event of war between the United States and Spain. Again the jury, this time after only 20 minutes’ deliberation, acquitted Burr.

All this and much more Newmyer recounts with meticulous scholarship, although sometimes in greater detail than may appeal to the casual reader. Trained as a historian rather than as a lawyer, he makes occasional errors in legal terminology and procedure, appearing, for example, at times to confuse the selection and function of grand and petit juries. Yet these rare imperfections, always trivial, do not interfere with the development and presentation of his narrative.

Aaron Burr has remained and will likely always remain a puzzling figure in the early history of the United States. Professor Newmyer may not have solved the puzzle, but his diligence and erudition have illuminated a chapter of history that should have special appeal for lawyers.

Walter Barthold is retired from the practice of law in New York City.