True rogues are more common in fiction than in life. That’s because a rogue has to be charming, persuasive, duplicitous, imaginative and opportunistic all at the same time. It’s easier to invent such a person than to be one. Aaron Burr managed it, and David O. Stewart’s “American Emperor” explains how.

Merely a talented lawyer and ambitious politician up to the age of 48, Burr had to change course after he killed Alexander Hamilton on the dueling grounds of Weehawken, N.J., in July 1804. Duels had taken on a distinctive cast in the new nation, where three-quarters of them were inspired by politics. There was even a congressional dueling spot in Bladensburg, Md. With politics no longer the preserve of the elite, partisan insults went public, inciting challenges such as Burr’s to Hamilton.

New York and New Jersey indicted Burr for murder, halting his law practice there. He was in his last year as vice president, and his political career was running out of steam. Put on the Republican ticket with Thomas Jefferson in 1800 because he could deliver New York, Burr had lost all credit with his Republican colleagues after conniving with Federalists when a tied vote in the Electoral College shifted the choice of the president to the House of Representatives, where Jefferson was the victor.

Burr’s roguish qualities manifested themselves when his term ended. He decided to go west and see if he could detach the frontier states of Kentucky, Tennessee and Ohio from the union, or exploit the discontent of New Orleans creoles newly incorporated into the United States by the Louisiana Purchase, or perhaps raise an army and wage war on Spain. As these possibilities suggest, the United States was anything but settled 25 years after independence. Stewart does a fine job of conveying the restlessness, resentment and unmoored fancies that prevailed among the men who had gone west to make their fortune while France, England and Spain continued to jockey for position in the New World.

“American Emperor” delivers a colorful narrative of the schemes that carried Burr from one reckless venture to the next. Of inestimable value in following his frenzied recruitment of allies are Stewart’s thumbnail sketches of “Leading Characters” at the front of the book.

’American Emperor: Aaron Burr's Challenge to Jefferson's America’ by David O. Stewart (Simon & Schuster)

Stewart gets his title from Burr’s plan to invade Mexico and set himself up as its liberator. Jefferson’s insistence on pursuing peace with Spain pushed Burr to turn to England and then France for backing. The former vice president could still meet with important people, eventually getting an interview with Napoleon in Paris.

As Burr pursued his bellicose projects, he was both secretive and indiscreet. You get the impression that just talking about his grandiose designs gave him pleasure. After a tour of the frontier, he teamed up with an Irish immigrant, Harman Blennerhassett, who offered funds and his island in the middle of the Ohio River as a site for collecting food, weapons and volunteers for a future assault on Spanish-controlled Mexico.

Stewart’s month-by-month chronicle of Burr’s machinations shows how cautious Jefferson could be. Only when the whisper of rumor had become a noisy chorus did the president issue a proclamation warning of the possibility of a conspiracy against the United States. Burr’s support then melted away.

Finally fully aroused by Burr’s perfidy, Jefferson had him charged with treason. Because Blennerhassett’s island was in Virginia, the trial took place in Richmond in August 1807, with Chief Justice John Marshall presiding. Burr’s team of lawyers included two former attorneys general of the United States. The prosecution included the lieutenant governor of Virginia and a future U.S. attorney general.

Stewart had an embarrassment of riches to draw upon for details about Burr’s trial, because the event was a match of legal titans, a cause celebre, a test of the new Constitution and a public circus. Almost all the attending luminaries left records, as did scores of court-watchers, such as the writer Washington Irving.

Even in this star-studded cast, Burr stood out as the most astute and adroit lawyer. Of course, he was fighting for his life. The enduring achievement belongs to Marshall, who drew so strict a definition of the proof necessary for levying war on the government that treason could not become a partisan weapon. By nipping the conspiracy in the bud, Jefferson had made it difficult to get the treason conviction he longed for.

“American Emperor” provides a full account of the trial, which led to Burr’s acquittal. Then, drawing on evidence not available to the jury, such as reports buried in French and English archives, Stewart makes a convincing case for Burr’s guilt. He calls Burr “a rival to Benedict Arnold for the title of most despised American.” Had Burr been convicted of treason, he might have earned that dubious distinction. As it is, today his bust is in the chamber of the U.S. Senate, where he served for a decade. One can imagine that, had Burr been condemned, “Aaron” would have been all but eliminated as a name for American boys, as Benedict Arnold’s treachery did for his first name.

Burr eventually got back his license to practice law, dazzling spectators with his courtroom performances well into his 70s. A rogue, yes, but also a remarkably resilient human being.

Joyce Appleby is a professor of history emeritus at UCLA and the author of “The Relentless Revolution: A History of Capitalism.”

AMERICAN EMPEROR

Aaron Burr’s Challenge to Jefferson’s America

By David O. Stewart

Simon and Schuster. 410 pp. $30