It's sad that Nicholas J. Karolides, Margaret Bald, and Dawn B. Sova, the authors of 100 Banned Books (1999) had no problem expanding the earlier edition to 120 Banned Books (2005).
At first I thought it would be fun to divide the books up into those that liberals banned vs. those that conservatives did. It turned out to be much less fun than I expected. While liberals and conservatives ban works on politics and social issues roughly the same, liberals didn't seem to have much of an interest with sex and religious books.
Also the categories aren't fair at all. I had to lump Stalin and Mao as liberal and the Vatican, John Calvin, Hitler, the KKK, and anti-porn activists as conservative. Also I can think of a few banned or challenged from a liberal point of view (such as Dr. Seuss's To Think That I Saw It on Mulberry Street) that were not included in the book.
For what it's worth, here's the four categories of banned books-- Literature Suppressed on Political Grounds, Literature Suppressed on Sexual Grounds, Literature Suppressed on Religious Grounds, Literature Suppressed on Social Grounds--with a brief description of who wanted to ban it and why.
Literature Suppressed on Political Grounds
All Quiet on the Western Front (1928)
Everyone - (Germans, Americans, Austrians, Hungarians, Bulgarians, and Yugoslavians) conservative and liberal: anyone who objected to its anti-war message.
Andersonville, MacKinlay Kantor [historic fiction of Civil War POW/Concentration Camp] (1955)
Conservative: Christian Action League, Answer for America, Concerned Citizens of Owens District, Daughters of the American Revolution, John Birch Society, Texans for America, and many independents angry over "filthy" language and negative portrayals of the Confederacy.
Animal Farm (1945)
Conservative: John Birch Society, United Arab Emirates.
Other: Kenyan government objected to negative portrayal of any one-party government
You Call It: Puritans and Royalists alike.
Black Boy, Richard Wright [Autobiography] (1945)
Conservative: Special Committee on Un-American Activities; the book's publisher (separated parts of the book dealing with Wright's adult life to another publication because of Communist involvement); Concerned Citizens and Taxpayers for Decent School Books; Concerned Citizens and Taxpayers for Better Education; and Taxpayers for Quality Education for language, racial conflict, that the author had been involved in the Communist party, and not promoting "traditional Judeo-Christian values."
Liberal: At least one complaint focused on the killing of a kitten which could be construed as from a liberal position.
Burger's Daughter, Nadine Gordimer [Novel of life in South Africa] (1979)
Conservative: The Republic of South Africa for portraying "whites as baddies, blacks as goodies."
Decent Interval, Frank Snepp [nonfiction about Vietnam policies] (1977)
Liberal: U.S. Department of Justice (under Carter).
Doctor Zhivago, Boris Pasternak (1957)
Liberal: Soviets for negative portrayal of Marxism and the Russian Revolution
Conservative: John Birch Society for a too sympathetic depiction of Soviets--apparently they didn't randomly eat each other.
El Se or Presidente, Miguel Angel Asturias [Novel of life in Guatemala] (1946)
Conservative: Carlos Castillo Armas's Guatemalan government
The Fugitive, Pramoedya Ananta Toer [Indonesian novel] (1950)
Conservative: Indonesian government for promoting Marxism
The Grapes of Wrath (1939)
Conservative: the Moral Majority and other fundamentalist minister groups, objecting to "obscene" language, "pornographic, filthy, and dirty" actions, portrayal of farms and government, taking the Lord's name in vain ("129 times, vulgar language, 264 times, references to sex - 31 times"). Irish, German, and Turkish governments.
Liberal: 1999 law suit against Puyallup, Washington school district that the book was racist ultimately led to an award of $7.5 million, creation of school offices of diversity affairs, and administrative changes.
Other: Pro-America, a women's group that objected more to the portrayal of California than anything else.
The Gulag Archipelago (1973)
Liberal (Soviets) Depiction of oppression and the penal system
The Hoax of the Twentieth Century, Arthur R. Butz [Holocaust denier] (1975)
Liberal: refused a place in Torrance City Library's banned book week; Canadian government; Northwestern University.
I am the Cheese, Robert Cormier (1977)
Conservative: Mainly school challenges for "vulgar" language, humanism, violating "Christian values," criticizing the government, and causing children not to trust governmental officials (this was before the Clinton administration).
In the Spirit of Crazy Horse (1983)
You call it: mainly libel suits by people named in the book.
Johnny Got His Gun, Dalton Trumbo [anti-war novel of WWI] (1939)
Conservative for vulgarity, sexuality, gruesome violence, unpatriotic sentiment, pacifism, (in Wisconsin in 1982, the book was challenged openly for being anti-war); House Committee on Un-American Activity)
Liberal: Trumbo himself (Republicans and right-wing groups used the book as an argument against involvement against Nazi Germany; the right claimed that Jews were suppressing the novel. During the war, the army declined to include the novel in packages of books distributed to troops).
Land of the Free: A History of the United States [textbook] (1965)
Conservative: The Tablet, a Catholic newspaper; the Textbook Study League, Inc. (formerly the National Anti-Communist League of America); United Republicans of California; the Concerned Parents of Rialto; and the John Birch Society); all of whom claimed the book favored communism and one-world government, was "slanted in the direction of civil rights," "mocks American justice," "ridicules religious beliefs," "fails to develop the great tradition of America, e.g., love of country, strong individualism, worship of God and private enterprise [note the lack of a comma between "God" and "private enterprise"].
Manifesto of the Communist Party (1848)
Conservative: German government, the Catholic Church, the House Committee on Un-American Activities, San Antonio Minute Women, pre-communist Russia, and many more.
In 1953, President Eisenhower told the nation "Don't join the book-burners" and defending the availability and the reading of Marx (but later made conflicting statements).
Mein Kampf (1925)
Liberal: various Jewish groups including the American Jewish Committee; various book publishers (usually including negative comments about Hitler in forewords).
Other: the German government, various other governments, Barnes and Noble, Amazon.com, E-bay (allows sale of English translation but not the original German version).
My Brother Sam is Dead, James Lincoln Collier and Christopher Collier [novel about the Revolutionary War] (1974)
Conservative: for vulgarity, "drinking and battlefield violence," "a negative approach to God," and being unpatriotic.
Conservative: John Birch Society, Rev. Len Coley, and others for language and sexual content, and being "a study of communism."
Liberal: No liberal groups or individuals were listed but I can't believe that no Marxist group challenged the book for its portrayal of communism
Novel without a Name, Duong Thu Huong [Vietnamese novel] (1995)
Liberal: Vietnamese government for negative depictions of Karl Marx, communism, and the Vietnamese government.
Paradise of the Blind, Duong Thu Huong [Vietnamese novel] (1988)
Liberal: Soviet and Vietnamese governments for negative depictions of communism, and the Soviet and Vietnamese government.
The Prince, Machiavelli (1542 original Italian; 1640 in England)
Religious: The Catholic Index, Huguenots, Anglicans, and Protestants in general (the book was blamed for the St. Bartholomew Massacre even though Catholics of the time were forbidden to read it)
Conservative and Liberal SUPPORT: both Mussolini and Castro vigorously encouraged the reading of the book
The Rights of Man, Thomas Paine (1791-2)
Monarchist British; various religious figures
Conservatives for bathroom language, unpatriotic, use of the Lord's name in vain; the book was "a tool of the devil," "anti-American, anti-Christian, anti-Semitic, and just plain filthy."
Spycatcher, Peter Wright [autobiography] (1987)
Conservative: Margaret Thatcher, MI5
The Ugly American, William J. Lederer and Eugene Burdick (1958)
Conservative: Joe McCarthy, House Un-American Activities Committee, usually for political depictions but sometimes the charges focus on the language; "filthy language and references to sex"
Liberal: Senator J.W. Fulbright (D-Ark.) for its portrayal of Americans
Uncle Tom's Cabin (1852)
Conservative: Pro-slave southerners; Tsar Nicholas I; banned in Italy but NOT included on the Catholic Index.
Liberal: for its portrayal of blacks
The Pentagon Papers (1971)
Conservative: Attorney General John Mitchell, Justice Department