Lately I've been reading The Viper on the Hearth, Terryl L. Givens' fascinating study of nineteenth-century anti-Mormon fiction. I thought it might be helpful to come up with a list of the digitized anti-Mormon novels  available on the Internet Archive, a good go-to place for nineteenth-century Mormonalia.

Here are the books I found:  

Belisle, Orvilla S.

---. The Prophets: Or, Mormonism Unveiled (1855)

---. In the Grip of the Mormons (ca. 1919) [This seems to be a reprint of The Prophets]

Bell, Alfreda Eva.

---. Boadicea, the Mormon Wife (1855)

Benoit, Pierre.

---. Salt Lake; A Novel (1922) [Translation from French]

Clark, Charles Heber.

---. Tragedy of Thompson Dunbar,  A Tale of Salt Lake (1879)

Curwood, James Oliver.

---. The Courage of Captain Plum (1908)

Doyle, Sir Arthur Conan.

---. A Study in Scarlet (1887)

Gash, Abram Dale

---. The False Star; A Tale of the Occident (1899)

Gilchrist, Rosetta Luce.

---. Apples of Sodom; A Story of Mormon Life (1883)

Grey, Zane.

---. Riders of the Purple Sage (1912)

Hannett, Arthur Thomas.

---. In the Days of Brigham Young (ca. 1914)

Henry, Alfred H.

---. By Order of the Prophet; A Tale of Utah (1902)

Hudson, Mary W.

---. Esther the Gentile (1888)

Kerr, Alvah Milton.

---. Trean; or, The Mormon’s Daughter (1889)

Mitchell, Langdon Elwyn.

---. Love in the Backwoods: Two Mormons from Muddlety, Alfred's Wife (1897) 

Paddock, Mrs. A. G. (Cornelia).

---. In the Toils; or Martyrs of the Latter Days (1879)

---. The Fate of Madam La Tour (1881)

Richards, Robert

---. The Californian Crusoe; or, The lost treasure found. A tale of Mormonism (1858)

Riddle, A. G.

---. The Portrait : A Romance of the Cuyahoga Valley (1874)

Spencer, Mrs. George E.

---. Salt-Lake Fruit : A Latter-day Romance (1884)

Stevenson, Robert Louis.

---. The Dynamiter  (1925)

Switzer, Jeanie Bartlett.

---. Elder Northfield’s Home; or, Sacrificed on the Mormon Altar. A Story of Territorial Days in Utah (ca. 1894)

Walsh, Marie A. (“Sandette”)

---. My Queen. A Romance of the Great Salt Lake (1878)

Wilson, Harry Leon.

---. The Lions of the Lord, A Tale of the Old West (1903)

NOTE: Absent from this list are the many anti-Mormon poems, memoirs, and histories written in the nineteenth century and early twentieth. Also absent are anti-Mormon novels not digitized on the Internet Archive.