Abbott retired in 1889 to devote himself to his literary and theological pursuits. Although most remembered for his mathematical satire Flatland: A Romance of Many Dimensions, published under the pseudonym A. Square, he authored many other books. Among his many works are Shakespearean Grammar (1870); Francis Bacon: His Life and Works (1885); the anonymous theological discussion The Kernel and the Husk (1886); three anonymously published religious romances-- Philochristus (1878), Onesimus (1882), and Sitanus (1906); Philomythus (1891); The Anglican Career of Cardinal Newman (1892); St. Thomas of Canterbury, His Death and Miracles (1898); as well as "The Gospels," an article published in the ninth edition of the Encyclopedia Britannica.
Abbott died on October 12, 1926.