Napolean Hill meets Dale Carnegie

The turning point in the writing career of Napoleon Hill is considered to have occurred in 1908 with his assignment, as part of a series of articles about famous men, to interview billionaire industrialist Andrew Carnegie, who at the time was one of the most powerful men in the world. Hill discovered that Carnegie believed that the process of success could be elaborated in a simple formula that could be duplicated by the average person. Impressed with Hill, Carnegie commissioned him (without pay and only offering to provide him with letters of reference) to interview over 500 successful men and women, many of them millionaires, in order to discover and publish this formula for success.[5]

As part of his research, Hill interviewed many of the most famous people of the time, including Thomas Edison, Alexander Graham Bell, George Eastman, Henry Ford, Elmer Gates, John D. Rockefeller, Sr., Charles M. Schwab, F.W. Woolworth, William Wrigley Jr., John Wanamaker, William Jennings Bryan, Theodore Roosevelt, William H. Taft, Woodrow Wilson, Charles Allen Ward and Jennings Randolph. The project lasted over twenty years, during which Hill became an advisor to Carnegie.[6] Mr. Hill was also an advisor to two presidents of the United States of America, Woodrow Wilson and Franklin Delano Roosevelt.[7]

Here is a video where Napolean Hill
explains meeting Andrew Carnegie.