Henry Louis "H. L." Mencken (September 12, 1880 – January 29, 1956), of Baltimore, Maryland, was a journalist, essayist, magazine editor, satirist, and acerbic critic of American life and culture, and a student of American English. Mencken, known as the "Sage of Baltimore", is regarded as one of the most influential American writers and prose of the first half of the 20th century.
The following Mencken quotes are often referenced in Harry Turtledove's work.
I detest converts almost as much as I do missionaries.
No one in the world, so far as I know, has ever lost money by underestimating the intelligence of the great masses of the plain people. Popular culture has usually paraphrased this line as No one ever went broke underestimating the intelligence of the American people.
H.L. Mencken in "The House That George Built"
In February 1941, H. L. Mencken stopped in at a Baltimore establishment called George's Restaurant for a beer. He listened attentively to the owner, former minor league baseball player, George Ruth, reminiscing about his life and career. It was Ruth's contention that had one or two crucial events been different at the very start of his career, he would have been remembered as one of the game's greatest players.
Mencken listened dutifully and attentively as he drank, often internally disputing Ruth's points. Once Ruth concluded, Mencken was reminded first of Thomas Gray's "Elegy", which contained the line Some mute inglorious Milton here may rest. Mencken had written a response some years before: There are no mute, inglorious Miltons, save in the imaginations of poets. The one sound test of a Milton is that he functions as a Milton. He could not accept that Ruth could have been another Buzz Arlett. He didn't share this with Ruth, but instead finished his beer, thanked Ruth and went back about his business.