Dale Breckenridge Carnegie (originally Carnagey until 1922 and
possibly somewhat later) (November 24, 1888 – November 1, 1955) was
an American writer and lecturer and the developer of famous courses
in self-improvement, salesmanship, corporate training, public
speaking and interpersonal skills. Born in poverty on a farm in
Missouri, he was the author of How to Win Friends and Influence
People, first published in 1936, a massive bestseller that remains
popular today. He also wrote a biography of Abraham Lincoln, titled
Lincoln the Unknown, as well as several other books. Carnegie was
an early proponent of what is now called responsibility assumption,
although this only appears minutely in his written work. One of the
core ideas in his books is that it is possible to change other
people's behavior by changing one's reaction to them.