At her death, Barbauld was lauded in the Newcastle Magazine as "unquestionably the first [i.e., best] of our female poets, and one of the most eloquent and powerful of our prose writers" and the Imperial Magazine declared "so long as letters shall be cultivated in Britain, or wherever the English language shall be known, so long will the name of this lady be respected." She was favourably compared to both Joseph Addison and Samuel Johnson, no mean feat for a woman writer in the 18th century. But by 1925 she was remembered only as a moralising writer for children, if that. It was not until the advent of feminist literary criticism within the academy in the 1970s and 1980s that Barbauld finally began to be included in literary history.
Barbauld's remarkable disappearance from the literary landscape took place for a number of reasons. One of the most important was the disdain heaped upon her by Samuel Taylor Coleridge and William Wordsworth, poets who in their youthful, radical days had looked to her poetry for inspiration, but in their later, conservative years dismissed her work. Once these poets had become canonised, their opinions held sway. Moreover, the intellectual ferment that Barbauld was an important part of—particularly at the Dissenting academies—had, by the end of the 19th century, come to be associated with the "philistine" middle class, as Matthew Arnold put it. The reformist 18th-century middle class was later held responsible for the excesses and abuses of the industrial age. Finally, the Victorians viewed Barbauld as "an icon of sentimental saintliness" and "erased her political courage, her tough mindedness, [and] her talent for humor and irony", a literary figure that modernists despised.
As literary studies developed into a discipline at the end of the 19th century, the story of the origins of Romanticism in England emerged along with it; according to this version of literary history, Coleridge and Wordsworth were the dominant poets of the age. This view held sway for almost a century. Even with the advent of feminist criticism in the 1970s, Barbauld still did not receive her due. As Margaret Ezell explains, feminist critics wanted to resurrect a particular kind of woman—one who was angry, one who resisted the gender roles of her time, and one who attempted to create a sisterhood with other women. Barbauld did not easily fit into these categories and it was not until Romanticism and its canon began to be re-examined through a deep reassessment of feminism itself that a picture emerged of the vibrant voice Barbauld had been.
Barbauld's works fell out of print and no full-length scholarly biography of her was written until William McCarthy's Anna Letitia Barbauld: Voice of the Enlightenment in 2009.
Her adopted son Charles grew up to be a doctor and chemist; he married a daughter of Gilbert Wakefield. Their child, Anna Letitia Le Breton, wrote literary memoirs, including Memoir of Mrs. Barbauld, including Letters and Notices of her Family and Friends in 1874.