In the annals of America’s first ladies, Louisa Catherine Adams has been overshadowed by her more famous mother-in-law, Abigail. The fact that her husband’s presidency was less than successful may have something to do with her own relative obscurity.

But as Margery M. Heffron’s new biography makes clear, this talented, tormented and fascinating figure is worthy of greater attention. It’s not too much to say that its pages make Louisa seem positively heroic.

Ms. Heffron died in 2011 before completing the book she intended to write. (Her manuscript was edited by her brother David L. Michelmore, a former editor at the Pittsburgh Post-Gazette.) She approaches her subject with both a commitment to exacting scholarship and a feel for a great story. She debunks myths and re-evaluates old judgments about Louisa and her brilliant but irascible spouse, John Quincy Adams.

Drawing upon her subject’s voluminous letters and autobiographical writings, Ms. Heffron’s account of Louisa’s life and times has the narrative sweep of a 19th-century romantic novel, spiced with sexual mischief, political conflict and family tragedy.

Louisa Catherine Adams never seemed destined for the ordinary. Her father, Joshua Johnson, was a London-based American merchant known for his lavish habits and questionable finances; her mother Catherine was beautiful, witty and (possibly) a former prostitute.

Educated in England and France — and the only first lady born outside the United States — Louisa was already an accomplished young woman when she met her future husband during one of his diplomatic missions in London. Ms. Heffron captures the “excruciating” nature of the couple’s long courtship, noting that Louisa and John Quincy “mirrored and reinforced the other’s least attractive and most vulnerable characteristics.” For all its unhealthy aspects, the two shared a genuine and enduring love.

A key subplot in this tale is the collapse of Joshua Johnson’s fortunes two weeks after Louisa’s marriage. She never got over the shame of her father’s bankruptcy, not to mention the suspicion that she somehow tricked the son of an American president into marrying a woman from a scandal-wracked family.

Going deep into the couple’s shared psychology, Ms. Heffron shows how this stain on Louisa’s name contributed to the “patently false” personas that the couple adopted in their marriage.

Though John Quincy attempted to play the “wise counselor” to his “sweet, submissive” wife, Louisa chafed at the bounds placed upon her. She battled chronic illness and depression for most of her married life while her husband pursued his career as a diplomat and statesman.

There’s much more to this story than marital angst and martyrdom, though. Amid migraines, fainting and a series of miscarriages, Louisa excelled at diplomacy during John Quincy’s stints as ambassador to Prussia, Russia and England.

Making up for her husband’s lack of social graces, she helped project a favorable impression of America among the European aristocracy. Ms. Heffron gives plenty of space to Louisa’s vivid descriptions of royal court intrigue, including the Russian Tsar Alexander I’s attempts to seduce her younger sister Kitty.

The book’s dramatic high point is its account of Louisa’s 2,000-mile carriage ride across war-torn Europe in the winter of 1815. Accompanied by her 7-year-old son Charles and several adults, she braves swamps, harsh weather and revolutionary violence as she travels from St. Petersburg to meet John Quincy in Paris.

She keeps her wits about her even while surrounded by a bloodthirsty mob of Napoleon partisans at the French border. “Never again would she accomplish anything that would give her such pride,” says Ms. Heffron of this life-changing experience.

Ms. Heffron makes clear that Louisa sacrificed both her own comfort and the well-being of her children to advance John Quincy’s ambition to be president. Separated from her two older sons for years while overseas, she watched them grow up emotionally damaged by their father’s unreasonably high expectations. Her regrets as a mother contrasted with the glittering success she achieved as a Washington hostess after her return to America.

Despite her sorrows, Louisa performed admirably as John Quincy’s de facto campaign manager during his run for the presidency in 1824. Thanks in part to her well-attended parties and personal lobbying of power brokers, her husband made it to the White House (after some controversial maneuvering in the Electoral College).

It is tragic that Ms. Heffron didn’t live to continue Louisa’s story beyond this point. As it is, her biography is nothing less than captivating, an engrossing read for both the serious history buff and the general reader alike. Reflecting back upon her life, Louisa Catherine Adams felt she’d “accomplished little of value.” This book argues to the contrary with skill, insight and passion.

First Published: June 15, 2014, 2:32 a.m.