On February 18, 1885, Mark Twain publishes his famous–and famously controversial–novel The Adventures of Huckleberry Finn.

Twain (the pen name of Samuel Clemens) first introduced Huck Finn as the best friend of Tom Sawyer, hero of his tremendously successful novel The Adventures of Tom Sawyer (1876). Though Twain saw Huck’s story as a kind of sequel to his earlier book, the new novel was far more serious, focusing on the institution of slavery and other aspects of life in the antebellum South.

At the book’s heart is the journey of Huck and his friend Jim, a runaway slave, down the Mississippi River on a raft. Jim runs away because he is about to be sold and separated from his wife and children, and Huck goes with him to help him get to Ohio and freedom. Huck narrates the story in his distinctive voice, offering colorful descriptions of the people and places they encounter along the way. The most striking part of the book is its satirical look at racism, religion and other social attitudes of the time. While Jim is strong, brave, generous and wise, many of the white characters are portrayed as violent, stupid or simply selfish, and the naive Huck ends up questioning the hypocritical, unjust nature of society in general.

Even in 1885, two decades after the Emancipation Proclamation and the end of the Civil War, The Adventures of Huckleberry Finn landed with a splash. A month after its publication, a Concord, Massachusetts, library banned the book, calling its subject matter “tawdry” and its narrative voice “coarse” and “ignorant.” Other libraries followed suit, beginning a controversy that continued long after Twain’s death in 1910. In the 1950s, the book came under fire from African-American groups for being racist in its portrayal of black characters, despite the fact that it was seen by many as a strong criticism of racism and slavery. As recently as 1998, an Arizona parent sued her school district, claiming that making Twain’s novel required high school reading made already existing racial tensions even worse.

Aside from its controversial nature and its continuing popularity with young readers, The Adventures of Huckleberry Finn has been hailed by many serious literary critics as a masterpiece. No less a judge than Ernest Hemingway famously declared that the book marked the beginning of American literature: “There was nothing before. There has been nothing as good since.”

READ MORE: Mark Twain & the Boyhood that Inspired His Classics