From a Wall Street Journal story by John J. Miller headlined “A Newspaper Taught Hemingway to Write”:

Ernest Hemingway worked at the Kansas City Star for less than seven months—between graduating from high school in 1917 and driving a World War I ambulance in 1918—but the job launched him as a professional writer, and he knew how much he owed to the newspaper’s style guide.

“Those were the best rules that I ever learned for the business of writing,” he said in 1940. “I’ve never forgotten them. No man with any talent, who feels and writes truly about the thing he is trying to say, can fail to write well if he abides by them.”