

No known source in Twain's works.
The earliest known source is a Usenet post from November 2000 https://groups.google.com/forum/message/raw?msg=israel.francophones/j_b0peHVcJw/YN5cG6Pdk6QJ.
Disputed
Act I, sc. i.
The Critic (1779)
No known source in Twain's works.
The earliest known source is a Usenet post from November 2000 https://groups.google.com/forum/message/raw?msg=israel.francophones/j_b0peHVcJw/YN5cG6Pdk6QJ.
Disputed
“To be completely cured of newspapers, spend a year reading the previous week’s newspapers.”
Source: The Bed of Procrustes: Philosophical and Practical Aphorisms (2010), p. 21
“I read the newspapers avidly. It is my one form of continuous fiction.”
Interview in The Times (29 March 1960), p. 7
1950s
“Half the American people never read a newspaper. Half never vote for President — the same half?”
Sometimes quoted as: Half of the American people never read a newspaper. Half never voted for president. One hopes it is the same half.
[Bill, Maxwell, http://www.sptimes.com/2002/07/07/Columns/In_gloomy_times__let_.shtml, In gloomy times, let's try to find a sense of humor, St. Petersberg Times, 2002-07-07, 2008-10-04]
Variant: Half of the American people have never read a newspaper. Half never voted for President. One hopes it is the same half.
Source: 1990s, Screening History (1992), Ch. 1: The Prince and the Pauper, p. 5
“Take your Bible and take your newspaper, and read both. But interpret newspapers from your Bible.”
“People don't actually read newspapers. They step into them every morning like a hot bath.”
Source: 1990s and beyond, The Book of Probes : Marshall McLuhan (2011), p. 184
Source: Life and Adventures of Peter Porcupine (1796), P. 22.
On the political cartoons of Thomas Nast in Harper's Weekly, as quoted in "Article IV: An Episode in Municipal Government" by Charles F. Wingate in The North American Review (July 1875), p. 150