H.L. Mencken
Mencken shows up on the GRE from time to time, usually in regards to The American Language because it is a seminal work in how Americans speak.
From Wikipedia:
a twentieth century journalist, satirist and social critic, a cynic and a freethinker, known as the "Sage of Baltimore" and the "American Nietzsche". He is often regarded as one of the most influential American writers of the early 20th century.
Perhaps Mencken's most important contribution to American letters is his satirical
style. Mencken, influenced heavily by Mark Twain and Jonathan Swift, believed
the lampoon was more powerful than the lament; his hilariously overwrought
indictments of nearly every subject (and more than a couple that were unmentionable
at the time) are certainly worth reading as examples of fine craftsmanship.
The Mencken style influenced many writers; American author Richard Wright
described the power of Mencken's technique (his exposure to Mencken would
inspire him to become a writer himself). In his autobiographical Black Boy,
Wright recalls his reaction to A Book of Prefaces and one of the volumes of
the Prejudices series:
“I was jarred and shocked by the clear, clean, sweeping sentences ...
Why did he write like that? I pictured the man as a raging demon, slashing
with his pen ... denouncing everything American ... laughing ... mocking God,
authority ... This man was fighting, fighting with words. He was using words
as a weapon, using them as one would use a club ... I read on and what amazed
me was not what he said, but how on earth anybody had the courage to say it.”
The American Language
The American Language is H. L. Mencken's 1919 book about changes Americans had made to the English Language.
Mencken was inspired by "the argot of the colored waiters" in Washington,
as well as one of his favourite authors, Mark Twain, and his experiences on
the streets of Baltimore. In 1902, Mencken remarked on the "queer words
which go into the making of 'United Statese.'" The book was preceded
by several columns in The Evening Sun. Mencken eventually asked "Why
doesn't some painstaking pundit attempt a grammar of the American language...
English, that is, as spoken by the great masses of the plain people of this
fair land?" It would appear that he answered his own question.
In the tradition of Noah Webster, who wrote the first American dictionary,
Mencken wanted to defend "Americanisms" against the English, whom
he increasingly detested.
The book discusses the beginnings of American variations from English, the
spread of these variations, American names and slang over the course of its
374 pages. According to Mencken, American English was more colourful, vivid,
and creative than its British counterpart.