In 1939, the city of Boston tore down a small house that was obstructing the view of a monument of Paul Revere. This action was an apt metaphor. The house had belonged to Jane Franklin Mecom, the youngest sister of Benjamin Franklin. And she lived in an era in which women were kept low to make way for enlightened men.

It is not the life of Benjamin Franklin, but rather that of his unremarkable sister Jane that is detailed in “Book of Ages: The Life and Opinions of Jane Franklin,” by Harvard historian Jill Lepore. Lepore, who has won awards both scholarly and popular — including being a finalist for both the Pulitzer Prize and the National Book Award — would be the first to point out that Jane is only unremarkable in the narrowest sense. We know practically nothing about Jane, and therefore cannot remark much about her. Yet, we can tell she had a fiery wit, no small amount of courage, and that, but for the discriminatory strictures of her time, she might have been as great as her brother.

Or at least, some woman might have. “Book of Ages” is much more than a biography; it is a story about how the 18th century world differed for different genders. As children, Benny and Jenny — as Benjamin and Jane were known — were similarly precocious. Benjamin was able to escape boredom, obtain a (self) education, and carve out a place for himself. Jane married at 15, was quite possibly raped, bore 12 children, and barely learned to read. “Her days were days of flesh,” Lepore tells us, “the little legs and little arms, the little hands, clutched around her neck, the softness. Her days were days of toil.”

“Book of Ages” is also a story about how to read silence — and spin a narrative from invisible thread. The first letter we have from Jane’s own hand was written when she was 45 years old. Her entire life until that point must be gleaned from her later recollections, from her family history, from her brother’s off-hand comments, from responses to her letters that have survived (men’s letters were much more likely to survive), and from a lot of useful context. Revolution was just a twinkle in the American eye when Jane was growing up. Waste ran in the streets of Boston. The Franklin family prized its soap recipe above all else. Only the daughters of the wealthiest men learned to write more than their own names. Jane, the daughter of an artisan, was lucky.

Lepore follows Jane’s husband into debtor’s prison and Jane’s brother into mansions. She lived a long life, and her surviving letters allow Lepore to figure out much of it. Jane also wrote a “Book of Age’s [sic],” which enthralls Lepore. Using paper she made herself, Jane created this book to record the births and deaths of her nuclear family members. The “Book of Age’s” tells a heart-wrenching story, all too typical for an eighteenth century mother — 12 children born, only one to survive to adulthood. A daughter. Jane.

Lepore follows Jane through the Revolution, through her brother’s rise and the king’s fall. That story is old news, but it is new and poignant when seen through the eyes of someone who had no political power at all. The book ends after Jane’s death, as Lepore miraculously traces the fate of her belongings — books, personal items and letters.

Perhaps the happiest facet of Jane’s life was her death: She had lived to a ripe old age and her death was peaceful. This was remarkably rare for her time. In her final years, Jane had the fortune of relative comfort. She spent her last days surrounded by great-grandchildren, reading everything she could. She also wrote the bulk of her surviving letters during this time — when she and Ben grew fat together.

To be sure, “Book of Ages” isn’t perfect. As many reviewers have pointed out, it’s self-indulgent. Lepore spends pages pondering things only peripherally related to the book at large, such as pages and pages of painful detail about the Frankln family soap recipe. And Lepore’s manner of writing can sometimes get annoying. She likes short sentences. A lot. She likes short sentences and repetition and strange phrases stuffed with deep-sounding symbolism. A lot of which is crap.

Nonetheless, “Book of Ages” should be a model for future biographers and historians alike. Biographers: Write a biography that tells a story so much larger than that of a single individual. Historians: Write a book that is engaging to the general public — as Lepore has.