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 considered as the 20th Century pioneer in the Self-Help movement when he published the book "How to Win Friends and Influence People" in 1936. It was very successful that it sold over 15 million copies, available in most major languages, and still is up to now, one of the biggest overall best-sellers in the self-help/improvement genre.
