How a generation of American writers took inspiration from Ralph Waldo Emerson’s provocative, irresistible ideas.

It is a remarkable fact that American transcendentalism’s two best-known authors—Ralph Waldo Emerson and Henry David Thoreau—lived within walking distance in the same small village of 2,000 souls. Like the Renaissance London of Shakespeare and Marlowe or the mid-20th-century Liverpool of Lennon and McCartney, antebellum Concord, Mass., was a surprising hub of genius, a confluence of talent that defies easy explanation.

The two men’s writings—a significant portion of what we call transcendentalism—remain some of the most important literary and philosophical statements in United States history. Transcendentalism was a heady mixture of European Romanticism and Enlightenment theology, born of dissatisfaction with the materialistic and increasingly industrialized culture of antebellum America. Its insistence on the inherent capacities of each individual—on the divinity within shared by all people—led to its antipathy toward any social institution that prevented people from realizing those capacities. And its optimistically rebellious impulse has remained durable now for nearly two centuries.

At the center of the ferment was Ralph Waldo Emerson. He was by no means the first person to articulate transcendentalist ideas—that distinction belongs to a now-forgotten coterie of young Unitarian ministers in and around Boston—but he was easily the most eloquent. “Our age is retrospective,” he proclaimed in his first major work, “Nature,” published in 1836. “It builds the sepulchres of the fathers . . . The foregoing generation beheld God and nature face to face; we, through their eyes. Why should not we enjoy an original relation to the universe?” He was declaring a second American Revolution, this one aimed at the mind instead of the political establishment.

If Emerson had been the only person to make such an argument, he would probably have come down through the ages as a minor figure, a New England crank. But his words rallied others, and his influence among a group of intellectual fellow travelers quickly made him, as one 20th-century critic put it, “the cow from which the rest drew their milk.” Among his followers were Boston educator Bronson Alcott, father of Louisa May; Margaret Fuller, who transformed transcendentalist ideas into an early, potent treatise on American feminism; Walt Whitman, who read Emerson’s essay “The Poet” as a mission statement for his own poetic project; and, most famously, Emerson’s fellow townsman Henry David Thoreau, who took to heart the older man’s call to “go cherish your soul; expel companions; set your habits to a life of solitude.”

Although born and bred in Boston, Emerson moved to the small town of Concord after the death of his first wife at the age of 20 and his renunciation, soon after, of the Unitarian ministry. In so doing, he was returning to the home of his grandfather, a member of that “foregoing generation” he had decried in “Nature.” Here he could think and write, intermixing these activities with planting pear trees or walking to Walden Pond. And here, in his tall white house on the Cambridge Turnpike (now a tourist attraction), he hosted a collection of acolytes and disciples and oddballs whom one friend called “Waldo’s Menagerie,” describing an afternoon during the peak of transcendentalism when she “looked in the parlour . . . and saw him sitting in that circle,—it gave me a feeling of horror—men with long beards, men with bare feet.”

Concord is the subject of Robert Gross’s monumental “The Transcendentalists and Their World,” easily the most comprehensive work ever written about the town’s social history during the transcendentalist era. Mr. Gross is the author of the acclaimed “The Minutemen and Their World,” published nearly half a century ago and reprinted since in dozens of editions. The earlier book provided an in-depth peek at customs and social rhythms of the village as its local militia prepared to confront the British on the eve of the Revolution. The new work, although considerably longer, is a companion volume. “The Transcendentalists and Their World” continues Mr. Gross’s sustained focus on a town that was in many ways both representative of New England and yet wholly sui generis.

Mr. Gross’s historiography is patient, thorough, cumulative. Over a series of thematic chapters, we learn how Concord’s citizens worshiped; how they educated their children; whom they voted for; and how they prospered or failed in business. We get a glimpse at the sparse population of black citizens, who left behind scanty records. Mr. Gross not only combs local journals and letters but also tax records, sales receipts, broadsides and programs for the local cattle show and the town’s bicentennial celebration (at which last event Emerson delivered the keynote address). We learn how much acreage was allocated for a typical Concord yeoman farmer, as well as the scandal that surrounded the town’s Masonic lodge. The point of all this is to chronicle the shifting tides of political affiliation and the growing individualism in affairs of religion and business during the years Emerson and Thoreau were reaching intellectual maturity. In Mr. Gross’s telling, the first two decades of the 19th century predict the nation we live in today.

One of the most interesting figures to emerge in the account is the town’s tireless minister of 63 years, Ezra Ripley, who happened to be Emerson’s step-grandfather. A figure straight out of an 18th-century novel, Ripley wore the antique knee breeches and black frock coat of his youth his entire adult life. Much like the Puritan forefathers whose pictures he hung throughout the Old Manse (and which Nathaniel Hawthorne burlesqued when he came to live in that house after Ripley’s death and wrote “Mosses From an Old Manse”), the minister consistently preached the need for social cohesion in a community that seemed more and more on the verge of spinning apart. It was Ripley who tried to guide Concord through the rocky shoals of religious division, which rocked the town in the 1820s when a portion of his congregation splintered to create a more orthodox church. It was Ripley, too, who served on education committees, hoping to develop in local children a sense of enlightened social duty. And it was Ripley who donated land for the erection of a commemorative obelisk to mark where the first shots of the Revolution had been fired, an achievement that occurred only after decades of squabbling over the location and appropriations for such a memorial.

As Mr. Gross makes clear, there was discord in Concord. The village, founded as the first inland settlement of the Massachusetts Bay Colony, had gradually fallen away from the communitarian ideals of the Puritans, a process that accelerated in the 19th century. By 1820, as business came increasingly to reward enterprising individuals and as congregants searched for a personal religion, the town adhered to the sort of individualism addressed in Emerson’s most famous essay, “Self-Reliance.” Transcendentalist philosophy, while considered with quizzical bemusement by the majority of the town, nevertheless articulated a form of self-development nearly every citizen would have embraced.

One of the most fascinating chapters in Mr. Gross’s account examines a number of young men and women of the village who fell under the spell of Emerson’s thought. George Moore and John Shepard Keyes were both young men who found themselves uninspired by their career choices and eager to improve themselves. Like their fellow citizen Thoreau, who moved to Walden in 1845 after an unsatisfactory stint as a schoolteacher, they were young adults at loose ends. Moore avidly imbibed Emerson’s lectures, chronicling their impact on him in a journal. Keyes, too, considered the transcendentalist’s speeches “a revelation.” Although Emerson didn’t overtly change the direction of their lives—Moore became a minister and Keyes the sheriff of Middlesex County as well as the village’s superintendent of public grounds—their encounter with their famous townsman’s thought changed the way they considered their life choices. It provided them each with a greater sense of agency.

What happened with the young women of Concord was more complex. Emerson’s lectures and essays primarily address a male audience; he typically resisted the emotional claims that mobilized female temperance and antislavery movements. Yet many of his most ardent supporters were young women, including Martha Prescott (who later married John Shepard Keyes), a storekeeper’s daughter, who wrote that she preferred “a Life of single blessedness, if I may only have time to read & study & can escape cooking & all other ‘about house’ horrors.” Similarly, the daughters of Moses and Frances Jane Prichard exchanged a lively series of letters discussing Emerson’s calls for self-reliance and a life devoted to higher ideals.

But in discussing Martha Hunt, the daughter of a hardscrabble farmer who struggled to make ends meet for his large family, Mr. Gross suggests the limits of transcendentalist thought. Hunt was an exemplary student. Emerson and Margaret Fuller took special interest in her, lending her books, encouraging her studies, and she was eventually sent to an elite academy 20 miles from Concord. But when she returned to the village to teach school—her family was too poor for her to continue her education indefinitely—she succumbed to despair and drowned herself in the Concord River. (It was this incident that partly inspired the death of Zenobia in Nathaniel Hawthorne’s “The Blithedale Romance.”) Hunt’s story suggests how the benefits of transcendentalist self-development were distributed unevenly among the town’s populace.

Mr. Gross wisely does not claim that Concord was the source of that philosophy. Rather, the town, by hosting two of America’s greatest writers, came to infuse their thinking with a peculiarly local flavor. If there were moments of tension between Emerson and Thoreau—“Talked, or tried to talk, with R.W.E.,” wrote Thoreau; “lost my time—nay, almost my identity”—they also often brought out the best in each other. When Emerson said in 1841 that “part of the education of every young man” should be to put himself “into primary relations with the soil and nature,” he had Thoreau in mind. It was Emerson’s woodlot on the banks of Walden Pond that provided the younger writer with the spot in which to live out the experiment in simplicity that resulted in his great masterpiece “Walden.”

Concord’s response to its two most illustrious citizens was alternately puzzled, proud and dismissive. On occasion, it was outraged; when Emerson and Thoreau praised John Brown’s failed raid on Harpers Ferry in 1859, some town members hung an effigy of the insurrectionist in the village square with a note bequeathing Emerson “my execution cap, which contains nearly all the brains I ever had.” But by the end of the 19th century, the town had accommodated itself to the radical thinking of transcendentalism, transforming itself into a tourist destination with busts of Emerson and Thoreau sold in shops throughout town. Mr. Gross’s richly detailed account shows us how such a surprising conjunction of place and thought could occur.

Mr. Fuller is Herman Melville Distinguished Professor of American Literature at the University of Kansas.