Great literary works that come to mind in connection with abuse are:
David Copperfield by Charles Dickens. David is physically and mentally abused by his stepfather and then sent to work as a child in a factory.
Oliver Twist by Charles Dickens. Oliver suffers abuse as an orphan in a workhouse where the children are starved. Then he is abused by the the undertaker who takes him from Mr. Bumble and abused by the older boy, whose name I can't recall, who keeps calling him "workhouse." Then when Oliver runs away to London, he falls into the clutches of Fagin, who teaches him to be a thief, and also of Bill Sykes, who uses him in burglaries.
In Dickens' Nicholas Nickelby there is a wretched boy at the boarding school who is dreadfully abused by the wicked schoolmaster and his wife. He runs away with Nicholas when he returns to London.
Dickens' A Tale of Two Cities is full of incidents of abuse of the lower-class people by the aristocrats, and then of abuse of the aristocrats during the French Revolution.
Dickens' Little Dorrit describes the deplorable conditions of English debtors' prisons, and his Great Expectations has many descriptions of conditions in British prison ships and jails. Little Pip is also abused by his sister.
Dickens is probably the best author to refer to on the subject of abuse.
Two weeks before his father's imprisonment, young Charles was sent to work in a blacking warehouse, pasting labels on bottles of boot polish. He lived alone in poverty in rented lodgings while the rest of his family moved into prison with his father—a common practice at that time. John Dickens was released after three months, and Charles returned to school. Dickens always remembered and hated this period of his life and the degradation it seemed to entail. Yet here he first became familiar with the lower-class people who appear throughout his novels. Dickens also returns again and again in his books to prison scenes. (From eNotes Study Guide.)
In Victor Hugo's Les Miserables, the little girl named Cosette, who is the daughter of the prostitute named Fantine, is horribly abused by the Thenardiers, who are being paid to take care of her. Jean Valjean rescues Cosette and has her brought up in a convent. Jean Valjean himself is terribly abused as a convict who serves many years in the galleys for stealing a loaf of bread.
In Vladimir Nabokov's Lolita, Dolores Haze (aka Lolita) is sexually abused by Humbert Humbert and then by Clare Quilty.
An interesting and little-known novel is The Star Rover by Jack London. It describes the terrible abuse of convicts in his day. He lived from 1876 to 1916.
Mutiny on the Bounty by Nordhoff and Hall is full of descriptions of abuse of British seamen during the eighteenth century.
Fyodor Dostoevsky, who had a terrible life, wrote about abuse of prisoners in Siberia in The House of the Dead (1860), and many years later Aleksandr Solzhenitsyn wrote about the same subject in One Day in the Life of Ivan Denisovich (1963) and The Gulag Archipelago (1974-78). Both authors wrote from personal experience. Both were political prisoners.