Dale Carnegie was an American author, developer of popular self-improvement courses, and director of the Carnegie Institute for Human Relations who became one of the most influential figures in the field of personal development and self-improvement. Born in 1888 in Maryville, Missouri, Carnegie was the son of a poor farmer who instilled in him a strong work ethic and a love of learning. Despite facing financial challenges, Carnegie managed to attend college and eventually became a successful salesman and businessman.

In 1936, Carnegie published his most famous book, "How to Win Friends and Influence People," which became an instant success and a classic of the self-help genre. The book has sold over 30 million copies worldwide and has been translated into multiple languages. The book's central message is the importance of treating people with respect and kindness, and the power of interpersonal skills in achieving success in both personal and professional contexts. The book is widely considered one of the most influential books of the 20th century.

Carnegie's other notable works include "How to Stop Worrying and Start Living," which focuses on managing stress and anxiety, and "The Quick and Easy Way to Effective Speaking," which offers advice on public speaking and communication skills. He also founded the Dale Carnegie Institute, which offers courses in leadership, communication, and interpersonal skills.

Carnegie's teachings emphasize the importance of developing strong interpersonal skills, such as empathy, active listening, and effective communication. He believed that success in any field, from business to personal relationships, requires the ability to connect with others and build positive relationships.

Carnegie's approach to personal development and self-improvement was practical and action-oriented, emphasizing the importance of taking action and practicing new behaviors. He encouraged his readers and students to step out of their comfort zones and to take risks in order to achieve their goals.

Although Carnegie's work has been criticized for its simplistic approach and its focus on manipulating others for personal gain, his teachings have had a profound impact on millions of people around the world. His message of the importance of treating others with kindness and respect, and the power of effective communication, continues to resonate with readers and students today.

He died in 1955, after suffering from leukemia of the type Hodgkin lymphoma.