“It takes a great deal of history to produce a little literature,” Henry James once observed. Jonis Agee’s discursive new novel, “The River Wife” (Random House, 393 pages, $24.95), presents 150 years of one family’s history in rural Missouri, on the banks of the Mississippi River. But even after nearly 400 pages, Ms. Agee produces only a little literature. “The River Wife,” with its surfeit of one-dimensional characters and simplistic plot points, is a fine example of misguided overreaching. Ms. Agee’s expansive lens takes in the width of history, but not its depths, and the contours of her story might have been better served with the details afforded by a significantly tighter focus.

Ms. Agee begins with a familiar setup. The year is 1930. The pregnant, 17-year-old Hedie Rails has left her parents and wed Clement Ducharme, a dissolute older man, who receives mysterious, late-night phone calls that beckon him out of the house and off to God knows where. “Just sleep,” he tells Hedie. “I’ll be back before morning.” Hedie can’t, of course, and wandering their ranch house in the river town of Jacques’s Landing, she stumbles upon a row of diaries that soon disclose the scandalous history of the reckless family to which her life is now securely bonded. The tales readily consume Hedie. “Sometimes I read the words they had written,” she tells us. “Sometimes they visited me in dreams; on many occasions they spoke outright, out loud to me.”

The novel quickly assumes the voices of the women who wrote these diaries — women connected inexorably to the men of Jacques’s Landing, who seem to control, in mostly a pernicious way, their destinies. (“For the first time I knew what being a Ducharme wife meant,” Hedie realizes.) We shift first to the beginning of the 19th century and to Annie Lark Ducharme, the first wife of Clement’s grandfather. In 1811, Annie, 16, lies in bed in New Madrid. The historic earthquake shakes loose a roof beam, pinning Annie down. Her family abandons her for dead, and after several days she is rescued by Jacques Ducharme, a French fur trapper who makes her his bride. Together, they establish the eponymous landing.

Annie is a shrewd, plucky, daring woman whose love for Jacques never wavers, even as he begins to neglect her and pursue the sordid life of a river pirate. Her story is one of tragedy: The earthquake permanently cripples her legs, and she literally and figuratively hobbles through her life, until forces of nature again imperil it, this time without Jacques to save her.

After her demise, Annie appears as an apparition to the nearly half dozen heroines who take her place. In this way, she presides over Jacques’s Landing in both a benevolent and unsettling manner, acting as a dea ex machina for the unfortunate women whose lives, we discover, eerily mirror hers.

Among the stories found in the diaries, Annie’s is the most carefully-rendered and the most harrowing. When we leave Annie’s story, “The River Wife” descends into tedium. Ms. Agee introduces us to a barrage of characters, most of whom are sketched so thinly that we forget them as rapidly as they are thrust on us. There are fur trappers, river pirates, gamblers, swindlers, ranch hands, lawyers, society ladies, Civil War veterans, slave-traders, and their slaves. Even John James Audubon makes a cameo. Regrettably, Ms. Agee describes each with a fulsome sentimentality that serves only to exacerbate our indifference.

Although “The River Wife” centers on women, Jacques, ironically, dominates. Ms. Agee has created an omnipotent patriarch, who lives for so long that people begin to question his mortality. He is the only character whose life intersects with each heroine, and the women fall in love with him precipitously and irrevocably, defining themselves in the process. Yet Ms. Agee fails to paint a richly textured portrait of her leading man. There is genuine conflict over whether or not to like Jacques, but, even after we are led through three generations of his family, he remains an enigma.

Ms. Agee is right to recognize the connections that invariably exist between generations. Grandfathersandgrandmothersstabbed at their lives in the same way as fathers and mothers, sons and daughters. “There’s just no way of knowing the infinite devices we have to stitch ourselves together across time,” Ms. Agee writes. “How we come to hold hands with every dead person, every ghost, every wrong, every beloved.” It is not enough, however, to know merely that Clement subsists as a gangster, as Jacques did, and that one wife struggles through childbirth, as another doubtlessly will. These are mere skeletons of truths. The fleshy details hold actual understanding, and they shouldn’t be overlooked.

Mr. Peed is on the editorial staff of the New Yorker. He last wrote for these pages on the novelists Marianne Wiggins and Emily Mitchell.