Sewell saw Black Beauty as lessons in equine care more than as a literary story, so it is not surprising that some of the early critics appraised Black Beauty as a care guide as well as a novelistic form. Readers often thought that a veterinarian, coachman, or groom must have written the book because it was so accurate in its details. Regardless, Black Beauty, classified as “Juvenile” by libraries, is considered a children’s classic and one that changed the nature of children’s literature. It is true that readers usually first encounter this novel as children, and there are film versions aimed strictly at a juvenile audience. However, many readers, such as Sewell biographer Susan Chitty, realize that if the book was written to educate those who handle horses, then it was written for working class men, not children.

Furthermore, like so many other readers, Lucy Grealy, who wrote the “Afterword” for a recent paperback edition of Black Beauty, has discerned additional elements that adults can appreciate. Sewell’s novel, Grealy says, goes “into the darker crevices of human failures and frailties, cruelty and indifference to such cruelty.” Grealy admits that Black Beauty is “a loving fable in so many ways;” however, despite its happy ending for the protagonist, it is “also a deeply sad novel, a tragic account of human failure.”

But first, Black Beauty is about a horse. Frances Clarke Sayers, in an article entitled “Books That Enchant: What Makes a Classic?,” quotes a child as saying, “The fact remains that when you read Black Beauty you feel like a horse.” In a piece on Sewell for Children’s Books and Their Creators (Silvey), the comment is made that “Sewell’s careful descriptions let readers feel the bit tearing into Black Beauty’s mouth or the chills caused by a stable boy who doesn’t know enough to throw blankets on an overheated horse.” Such skillful detail illustrates and strengthens Sewell’s message about the need for kind treatment of horses.

Her detail and artistic talent also enliven the novel with elements of excitement. Critics have noted that the reader is captured by the action of the nighttime run to get the doctor for Mrs. Gordon, the flooded bridge, and the stable fire. A review of Black Beauty in The Critic in 1890 praises Sewell’s “skill in the art of narration,” writing that the story is more “readable than the average novel of today.”

Vincent Starrett, in an essay for Literary Appreciation, says that Black Beauty “is unquestionably the most successful animal story ever written.” He added that it is “certain that more than any other single agency this humane classic has improved the lot of the captive horse.”

The book was eventually adopted by both the British and American Societies for the Prevention of Cruelty to Animals, and thousands of copies were distributed for educational purposes. As a result, in the United States, a million copies were sold between 1890 and 1892, and Black Beauty continued to sell at the rate of a quarter million copies each year for another twenty years.

While some critics have found Black Beauty too sentimental and didactic, its success belies these criticisms. Sewell was not just a novice writer pounding on her pulpit. Critics have praised the way her sincerity and passionate convictions are combined with skillful characterization, clever juxtaposition of human and animal experiences, eloquent descriptions, and overall good storytelling.