Dale Carnegie was an American author, lecturer, and self-improvement guru. He was born in 1888 in Missouri and started his career as a salesperson. Carnegie's book, "How to Win Friends & Influence People," is one of the most influential self-help books ever written. It has sold over 30 million copies worldwide and has been translated into over 30 languages. Carnegie's work has had a profound impact on the personal development industry and has inspired millions of people around the world to improve their interpersonal skills and achieve their goals.